Interesting. SFrames (Surface Frames) also untrims surfaces so I used sFace (C# Shrink Faces) and moved on. Reading your post gave me another idea: lofting bottom and top edges.
I studied the code you posted, though it wasn’t easy… Challenge accepted, game on 
This version (‘d’) has 490 holes per surface fragment times 124 fragments = 60,760 holes and completes in less than three seconds 
Perforates one panel and uses Copy Trim for the rest.
facade_2025Jun13dd.gh (32.9 KB) (UPDATED)
I was lazy about using flatten a couple of times but otherwise, this is a huge improvement. 