I am buying a futaba 3pv this week and wondering if it has the button or option to use with my losi ten t ross starting system.

The 3pv only has 3 channels Steering (1) Throttle (2) and a left right switch (3) I assume this switch would be used for forward/reverse. It does not have the extra button.

The included receiver with the 3pv is only 3 channel as well.

You would loose your remote starting option unless there is some hidden feature in the menu I never saw.

There are lots of options on the 3pv because of the LCD screen and buttons. The 3rd Channel on the receiver would be meant to connect to another function, or to power a transponder or fan. I would consult some other experienced Futaba guy as I am more familiar with the Sanwa stuff. (Can't wait for the new M17 )