Have you tried cutting that using 2D toolpaths ?
If it were me I would just draw some vectors & then cut that using profile & pocket cuts, would probably save a lot of time & get a better finish at the same time.
Not sure I can help with your problem though
Bob has posted some good info, about the size of the model & it's position in your material block, what machining allowances are you using ?
what bits are you using & are you using the same bit for both the roughing & finishing toolpaths ?