It's possible to do multi-angle frames on a Morso, but not easy. For a start you have to cut the rails at 45° first (or saw them square) slightly over size and then reset the fences
to whatever angle - say 22.5° for octagonal. Here's the tricky bit. On an 8-sided frame you have 16 faces all of which must be spot-on angles. A slight deviation on one fence will be
multiplied 8x in assembly. The only way do get the set up right is to spend time cutting scrap pieces and dry-fit testing until there are no gaps in the joins. This could take hours.
Fine if you are doing a large run, but not for just a few frames. There is also the issue of getting the rails all the right length - no measuring stops.
Much simpler on a saw, as long as you have a saw where you can reset the blade angle.
Never cut this particular moulding btw.