A second attempt at the tutorial from Penta was reasonably successful.
The first attempt was most definitely not: the collet I used didn’t tighten up on the workpiece enough and the workpiece moved towards the mill during the operation. As I looked on in awe at the increasing size of the chips without thinking to intervene, the mill eventually plunged into the workpiece which then moved and snapped the mill. I have video but won’t publish that… As I said: not successful, beginner chips 🥹