yes you can
mix a switch together with your flight mode channel , set it so it offsets (can you see in the tools that i will show failsafe)
on mx-16 or MX-20 to set safely the failsafe function , don't set it in the TX side
but go in telemetry search throttle channel and make a fixed failsafe output range.
so the rest will be on hold (level) and flight mode on RTH