So there's a "perfect zone" like old MCH for using multitool skills instead of heated skills, but then if you overheat you get improved GCDs and multitool skills. So, which is being aimed for in this rework? You mention heat and overheat, are they separate gauges? Is the idea to hit max heat, then spend it down? Who would spend in the "perfect zone" when overheating gives so many more benefits?

This gauge has a lot of spenders in all the multitool actions plus Hypercharge, but no mention of how heat builds. Is it just from GCDs?

BRD and DNC already have enough proc-based mechanics, so there really isn't a need to give MCH a proc that introduces RNG in an obtuse way, especially if it's just a copy of what BRD already has.

Machinist's rotation should be a well-oiled machine, but this is rough and unrefined. It needs more effort put into it to convince people it has merit.