It seems the slicer is somehow struggling with the circular thin walls and can't decide if it should add infill or not.
It reminds me (a lot) of an older zsuite bug I reported where thin walled round tubes printed badly...it was squishing too much infill in between the two outer walls which made the surface bumpy/rough.
Try to print the model at a slightly different scale ...just for a test. Or could you maybe make the holes in the outer ring round or oval instead of rectangular? This would reduce the thin walled area. Or try to make the walls on the ring a bit thicker in general.
You should defnitely add this one to the bug tracker. This way the Z team can work on it efficiently.
You have to buy a Dremel. Best tool ever!
I actually use an older dental technician one (“Schick”)…can’t live without it. Makes clean ups and corrections so easy.