I'm working on the design of some large channel letters. A vendor is supplying the face plates with LED mounting recesses. I need to design my letters to fit his plates.

Vendor provided me with DXF files. Here's a sample of what they look like. The outline is composed of thousands of lines & arcs.

This creates significant performance issues in SW, because I need to use that outline to create all the other components of the letters. I tried converting to splines, but that wasn't a good solution as splines have a lot of limitations. I tried drawing over using tangent arcs, but it's very time consuming.

Does anyone know of a good solution for DXF clean up, either inside SW or additional software? What I want is a shape that is within 0.5mm of original shape, but drawn with the minimum number of arcs/ lines. Tangent arcs preferred, as they are best for CNC.