4th axis jewelry carving

I'm trying to generate a toolpath to make a ring on my rotary 4th axis.
Roughing with a 1/8" bit is fine but the problem is that Its taking way too long to generate the finishing path for the bits that i use.
I have 2 bits that i want to use for finishing. 0.3mm endmill and a 1/8" veemill / v-bit.

Could someone help me get around this problem?

Attachment 247756

After a week of continuous research I found that jewelers use .004 stepover when using a tapered bit. I've successfully milled a ring with those specs but it took about 5hours to calculate the toolpath. Is it normal for Rhinocam to take that long to calculate the toolpath?