Clocks - the main inputs on teletype itself are for that really- trigger on input 1 drives script 1 - the m script is a ‘self drive’ version of the same
The TXi is good for parameterising your scripts so for example
#I
TI.PARAM.MAP 1 0 4
#M
CV 1 N ADD P.NEXT MUL TI.PARAM 1 5
so in this really simple example - you have a pattern set up which you are playing with P.NEXT and knob 1 on the TXi transposes that pattern up by 5ths (you could easily do the same using a sequence coming in on one of the inputs so the transposing was automated)