The spindle is the stock Carvey “300W DC spindle”. On the roughing pass, I had the stepover set to the same as the finish pass (15%). This was definitely the culprit for the time.
I was just playing around with different settings in Cut3D and if I just switch the stepover in roughing to 40% is reduces the time by nearly 5 hours. I’ve also ordered a 1/4" collet and 1/4" ball end mill - that should take the roughing pass down to 23 minutes, which will get the whole carve down to under 2 hours.
Still learning, Iots of trial and error at this point - I appreciate the feedback!