This and the fork bending thread are valuable resources, IMO. Modifying a bicycle frame is tricky beyond geometry changes. there is hardly any material to work! These are lean machines to begin with and reworking can simply burn through the resources. Thin tubing requires preparation and exactitude to work with and I'm suspicious of it. I wouldn't buy a stretched frame, for example. Many of the builds on this site exemplify mods that do not heat the metal. This is a key point.
I was shopping earlier and Ruff frames, despite their announced cost drop, are still a lot of money! A free mod on an existing asset avoids all that cost! I think it's really a smart way to go!