I want to make tailpieces (the part that connects the strings to the body) with decorative carvings for string instruments like violins. This piece is actually a tailpiece for a Tagelharpa! (I added holes for the strings after taking this photo)
As for the finish, I’ll just use oil, without sanding to preserve detail in the carving.
I don’t know any slicers that do it exactly as you described. I know that in OrcaSlicer you can print perimeters at set layer height, but infill only everey Xth layer.