Rightly or wrongly I also cut by experience and feel. If I go past my trusted F&S or DOC I can usually hear the tool loading up and melting is often only a few seconds away. This can happen quite quickly if it goes around a corner or radius.

Pockets especially need a bit of thought - the first ramp into the new material is at full WOC, whereas once a small bit of the pocket has been cut and the current DOC value is reached then the WOC is generally 20-50% (50% is max in Vectric Cut 2D). This means that feeds and speeds are different for the getting started vs the rest of the clearance.

I can backoff F&S so that both situations are OK and you don't get melting, but then the whole job takes much longer. Or what I do is set the feed and speed for the general pocket clearance but manually override (using Mach3 slider bar) the initial ramp and first few passes of the cut to say 30-50% feedrate until it is into the pocket properly when I slide it back up to 100%. Maybe more advanced CAM software can give you options here but Vectric Cut2D does not.

I'm also stuck with 1.5kW spindle on ER11 (so 6.35mm max) which limits tool stiffness. I'm sure 8mm would be much better as Dean says.

When I cut slots (or outline profiles to cut something out) these are most likely to clog up when I'm about 8mm into the part, which is a problem when the part is 20mm thick. WD40 plus clearing the chips helps, along with a lower DOC than the first 8mm.