@maximassi
The reason for the lathe problem is that the workpiece is very small.
GrblGru works with a grid in order to be able to calculate the GCode as quickly as possible.
This grid can be set in the settings under 'Delta profile'. The default value of 1mm is too big for your component.
Set it once to 0.1. If you make the grid even smaller, the result will be more accurate, but then the calculation will take longer.
In the new beta version V3.42.3 on my website I have now added the Ctrl sequences for your joystick. But they only work if you have activated the focus button before. (see pic)
I will also send you a private message (PM) with my email address.