I have my MT12 for a week now, and bought for and use it on my crawler.

This things allow me the usual stuff that any radio can do, given enough channels. Such as movement, lights, winches, overdrive and dig.

But EdgeTX allows me to create mixes such as how I'm handling my winch.
It has a normal in/out on Trim 4, but I can also control it with my throttle in either self or helper mode.
Where 'self' is winching in and slowly moving forward on throtle, and 'helper' is winching in and moving backward. While having a wav file notifying what mode I'm in. (Oh and leds showing it as well.)

I can also have my winch locked, so I can't accidentily turn it on, while I'm trying to keep my own balance on some muddy incline.

That's the BIG thing about Edge/OpenTX: If you can think of it, you can program it. For mixes like my own, it has a crazy learning curve though, don't underestimate that.

What I DO consider an issue with the MT12 is a lack of real switches. Yes, you can use a trim switch as a switch, to control channels, but it's a lot of work. Also the two extra switches you can put on the base are seen by the radio as a pot, so you cannot assign that directly as a condition to turn a mix on or off. (You can work around that with Logical switches, which I've done).
EDIT: You need to setup the additional switches in the hardware menu. (As per the manual...)

For racing I don't really see the point. Also not sure what a race directors opinion is going to be when you show up with an ELRS protocol radio

Edit: Oh, and forgot to mention: You can't use Companion for it yet. That is planned for the next release of EdgeTX. 2.10, we're currently at 2.9