who'da thunk? It was always there, I just couldn't see it. Thanks, this will make my time with Oblivion much more enjoyable, I'm sure!
A note of caution: If you unpack the BSAs into your Oblivion\Data folder, you will see a
substantial increase in load times in game. I recommend unpacking them into a new folder (outside of Oblivion\Data), working on them there, then saving the modified meshes/textures/whatever into the Oblivion\Data folder.