That's very kind. Part v2-angle-part-centerb is the one that fails. I really am not concerned about saving filament with thin walls or holes. I can try to slice magnet-angle-1boxcentral and use that one.
I get the magnet holes on lots of files. Here's how v2-angle-part-centerc slices. But again, I don't need the thin walls. These might work fine with the original files, I just need to split those up so they fit on my printer.