Just a quick update...

After modifying the post processor it now starts and stops and cuts where it should at the correct height.

https://photos.app.goo.gl/GfUPKpiU7RNKK4fXA

(Only test cutting at -1mm so extraction was removed)

So for now, I'm a happy chappy.

I've also worked out how to drip feed code to it, so nearly 10 minutes of code streamed consistently no problem.

Obviously, taking onboard JAZZCNC's comments I'm aware that this may be a ticking time bomb so I would still really appreciate any thoughts/comments on controller/motor/electronics options.

As I have no clue what's good/bad general brand/manufacturer guidance would be a massive help...I can then research in more depth... Many thanks.