Cheers for that Dean. I’ve used feed hold several times so far, mainly when I’ve spotted my hold down clamping is not great so I can tighten up.

I also like your advice on not leaving the machine alone overnight. Apart from it getting lonely, I can see the issues if the pc has a hissy fit and stops sending code with the spindle still moving at 20,000rpm.

Perhaps a multi day cut is the way forward.