I intend to use maybe a 12F683 to pull a Transmitter Input pin LOW for a few m/s to make it transmit then hold the Tx pin high to stop false triggering via floating voltages if this is safe to do this without damaging the transmitter or pic
what is your doubt ?

the data so far indicates no need for pullups , the schematic shows none.

a pic pin when configured as output will never "float" its either high or low when set