Shayno's looks kind-of like what I'm up against. Except not only do I have a bunch of low-angle vertical panels coming together, but each panel also has low-angle horizontal angles too.

The only solution I could come up with was to extract a line from the corner, extrude it without caps, then shell the result and use that as a boolean. It's not quite what I wanted, but it's probably good enough.

Unrelated to this problem, but related to the project I'm working on, I realized that adding in a way to have smooth/rounded corners on the Inset tool like we've got in the Offset tool. I've been needing to make panels and wanted to have rounded corners on them. For some reason if I used Inset, then tried selecting the corner lines to Fillet, it wouldn't work.

-Paul