CNC lathe retrofitt - Feeler FTC-280

Hello i have a Feeler Ftc-280 which im currently retrofitting from its fanuc OT controller to a ethercat system. Some specifications so you know what im working with: 11kw fanuc main spindle (i will run it on a regular vfd with modbus ), 1.2kw x axis servo, 1.8kw z axis servo, 2.2kw hydraulic pump (for driving the turret, tailstock, probe arm, parts catcher and chuck). It´s a quite rigid machine weighing 5 tons with some 50mm thk ballscrews. I have purschased most electronis and have gotten the lichuan servo motors and beckhoff devices up and running. I already bought a raspberry pi so i will not be able use probe basic. Is there another nice gui for lathes?

The tailstock on the machine works by movving the z axis so it is aligned with the tailstock then a pin gets hydraullically pressed into the tailstock so when you now move the z axis it brings along the tailstock so you can move it to the desired position. Does anybody have a idea how i can make this. I tried to use a m100-199. But then i saw you canttt use subroutines. Otherwise ittt would be perfect since you can use its related parameters to set where you want to place the tailstock. Is it possible to use parameters with unallocatted mcode. So you could maybe do a m20p200?
 

After a couple of hours fiddiling with my vfd to get it working using modbus my pi4 died on me... not really sure what happened it just suddenly went black so i purschased a mini pc witth a celeron j4125 with dual ethernet ports.