first of all thanks for developing this program, it's great.
I've got few questions:
1.) can you add 1.0562 - S355J2 material to your database? It's what we mostly do.
2.) How do you look for rpm and feed for counterboring the hole plunging with an end mill? What depth of cut DOC and WOC do you enter ? is there any difference regarding existing pilot hole?
3.) I love your chamfering tool calculations, it matches how it's defined in fusion360 perfectly. However shouldn't there be a mini-calc similar to circle/ramp as you should reduce your feedrate while chamfering a hole, (or you could increase your feedrate while chamfering a boss).
Thanks and keep the good work.