Most digital servo's are limited to 333Hz due its possible max pulse width of about 2.1~2,2 msec (150% EPA setting) and you need to have a certain time low pulse tot tell the servo to reset and wait for the new pulse. Sanwa did stretch this (I believe SHR called) mode up to 384Hz because there is some room to shorten the low pulse.

But then the higher speed servo's in SSR mode use a center pulse width of 300 usec with the same 384Hz frame frequency, with this they could lower the latency by a little bit more than 1 msec. About SXR and SUR I do not know much than only SXR still uses the same 300 usec center pulse but with a higher framerate.

Futaba its SR works on an 833Hz frequency and have a center pulse of 760 usec, the SR mode of the FlySky transmitter goes up to 1000Hz because as with the Sanwa slight higher frequency there is the room for it. Futaba UR is at 1600Hz with a center pulse of 190 usec

Providing any signals a servo is not made for will result in a weird behavior, like putting a 1000Hz on a 333Hz limited servo is basically is impossible with a needed pulse width of 1 to 2 msec. What is possible and I think done with some transmitters is only sending the info repeated on a much higher rate but the receiver puts out the signal limited to the servo, In that case the receiver can determine what the right info is among some disturbed data.

I only wrote so much because I thought I would help you. Sorry for trying to help.

You really only needed to know two things: You can get what you need (extended PWM range) by choosing 8CH @ 333Hz. That's it. The devs on the github issue tried to tell you that repeatedly, and you got combative, so I tried to give more background thinking maybe you just didn't understand why they were telling you that. I tried to give you the "why".. Turns out, you are the one that doesn't have an open mind. You want what you want, and you don't care to listen to anyone else.

There's no way 1000Hz feels smoother than 333Hz because the servo cannot update faster than that anyway. That is in your head. And no, I don't think servos operate at a "much higher pwm refresh rate" than that -- it's technically impossible given the pulse width.

You're complaining about the UI/UX.. which is fine to do.. but ExpressLRS and EdgeTX... these are open source projects, which means they are volunteers. The technical capabilities of the system is top-notch and they are updated and improved constantly. This is why we are lucky to have this in the air and surface world as a CHOICE. That's why an MT12 with the same or better level of capability and performance as a $600-$1,000+ radio is available for $130. Yes, they can probably add more modes to make things even better. And they probably will. ExpressLRS came to us from the air world and they obviously need much more than 2 channels, so give it some time. In the meanwhile, what we have is MORE than sufficient for surface. 333Hz is more than anything you will need or feel. No one is forcing you to use this system. And people are kind enough to try to help you. But if you want a polished UI/UX, that might take some time. That's okay. Some of us are just fine with the UI and will gladly take the performance and capabilities available today. I, for one, am grateful I even have this choice. I'm not going to go to the volunteers and demand that they give me what I want and then accuse them of not listening. I'm sorry you don't feel this way, but I don't want others reading your rant to get the wrong impression and wrong set of facts.

Again, how can you set a 1000Hz frequency if you need at least a pulse of a 2 msec? Only with that knowledge you can not go higher than 500Hz and because you need a pause between the pulses as well the limit is below 400Hz. So with such pulses trying to create 1000Hz frame rate is impossible. The software must go berserk with such settings.

High response servos use a shorter pwm period, about half the typical 1800-2200us range. Even ELRS supports this. You should try to look into these things before being so dismissive.

Edit: rctech user showing 700hz frame rate from sanwa sur mode https://www.rctech.net/forum/showpost.php?p=15974952&postcount=5

Indeed. There's no way he can feel any difference because 1000Hz PWM is not possible with the given pulse-width required. Even without the extended range, running ExpressLRS at a packet rate of 1000Hz, the servos themselves are not getting refreshed at 1000. It's obvious when you set-up the ExpressLRS receiver. The maximum refresh rate when a channel is configured as a PWM output is 400Hz. For instance, the ER5C-i (and all ExpressLRS PWM receivers are similar) look like this for Channel 1's Output:

Does the DSM protocol for the 4-in-1 actually support faster than 16.5ms (60 Hz) frame rate? I believe that is what Spektrum DSM2 radios are running at, but "DSMR" runs at up to 5.5ms.

I browsed through a few of the DSM subprotocols on my MT12 with the external multi-module, and I believe they all have the option of 22 or 11ms. When bound to the DX3, I see pulses from the receiver for all but channel 2 at 180Hz with a scope. Channel 2 was 90Hz. I haven't looked at the pulses when bound to the multi-module, but it should be all 90Hz.

I'm being dismissive because there's no way you can feel the difference between F1000 Wide and 8CH Full @ 333Hz. The ExpressLRS PWM receiver you are using cannot output short-pulse PWM. The servo you are using cannot update faster than 333Hz... There is no way. That's why I am dismissive of that specific claim.

It can - it has an option for a pulse that's ~500 to 1000us, though it doesn't look like you can use that to run a higher response servo. It's hard to take you seriously when you don't know what you're talking about.

Anyway, I can feel what I feel regardless of what you believe.

And like I said, other top of the line radios and servos offer pwm frequencies significantly higher than 400hz, so elrs can't claim to be a totl system of it can't offer the same features. The devs are too ignorant of the surface market know elrs is deficient in that regard, and because they clearly have the same attitude as you, they will undoubtedly stay ignorant of it's shortcomings.

When you say "it can...." What can?

Look. I'm just saying, you created an "issue" on the ExpressLRS Github saying you can't get extended PWM range in F1000 mode. ExpressLRS doesn't currently support extended PWM range in F1000. so, it is working as intended. It is not a bug or unintentional behavior. It does not belong in an issue. People responded and told you what you needed to do to get extended PWM range. The extended PWM at 333Hz would've worked for the exact set-up you presented (a PWM receiver to a 333Hz servo). It's not an issue, and yet people tried to help you. They were right to close it. And then you claim they are being ignorant and not listening. Making this request for extended PWM is fine. Wanting it with higher packet rate is fine. But do it in a discussion post and not with a demanding tone to volunteers that put their heart into this project for everyone's benefit. I can't believe you can't see that.

I was searching where the Savox was mentioned but I had some contact with Savox in the past and they have no servo's supporting these faster response signals. The 1257TG just use the normal 1-2 msec signal and will not react to Futaba its 760 usec and Sanwa its 300 usec pulse. And no way you can make that work unless you hack the servo its firmware (beside the question if the processor is fast enough to work on those higher speeds)

Of course you can provide a signal of 0.5 to 1 msec because most normal servos can handel a pulse in the range of 0.5 up to 2.5 msec but your servo will have a limited move as well if you try to limit it to 1 msec.

I'm not saying I want my savox to react to higher frequency PWM signals - just that I think the car feels better when there's a faster packet rate between the radio and tx. Minor distinction. And also, if I want to upgrade to a servo with a faster PWM frequency, I won't be able to take advantage of it's improved performance with this radio due to the packet rate limits imposed by trying to transmit more channel's worth of data than I need for a car.

But as far as I can tell ELRS doesn't sync packet rate to PWM frequency. So a packet that shows up just after a PWM period begins will result in a slightly higher overall latency than if the packet rate was faster than the PWM frequency. Even in the case where a packet arrives just after the start of a PWM period, if more packets show up before the start of the next PWM period there will be less time delta between the most recent command I put into the radio and when the radio starts doing that thing.

Packet rate and pulse rate seem to be confused in this argument.
I'm running servos at 400hz which is ver the 384 sanwa and packet at f1000, packet is just having the updates ready for the pulse . Flysky is also 380hz at digital settings
Not sure if the OP understands that
Ive been playing with both trying to get it up to at least flysky speed

Bought an NB4+ on a whim after feeling a bit frustrated with this radio. It came in the mail today and either the NB4+ is better than the NB4 was, or I just forgot how good the old NB4 was, but man it feels so good compared to the MT12. It just feels much more precise and easier to control my car with the NB4 compared to the MT12. And FlySky actually supports and develops in the surface market whereas RadioMaster just copied a bunch of different peoples' work from the flight world, crammed it all into a surface radio, and as far as I can tell provide nothing back to the groups off of whose work they profit even after tossing an entire new user base at them. Ultimately they're who I should be upset with - they sold me a radio that shipped with firmware that causes signal dropouts and full throttle runaways and can't even make a steering servo rotate its full range.

I'm done with this radio.

Thank you. Thank you so much for doing that.