That's a great help. I also found that most model changes (armor, clothing, weapon, masks) make the game crash. The only models I've been successfully able to integrate are lightsaber models from Jorn's KotOR lightsaber pack. Those work great without even using the patcher, but just moving the files (I started with a clean Override and didn't have any conflicting .2da files).
So after you moved the KOTOR Data folder out of the package and ran the TSL patcher mods and model mods, did the models that caused a crash before work alright? It wasn't perfectly clear from your post.
Also, when I try moving the above-mentioned folder out of the package, it begins a lengthy process of copying it instead of moving it (it doesn't happen in the reverse direction). How did you get around that?
And finally, I use CrossOver to install TSL patcher mods, and it can find the KOTOR Data folder even inside the package and install things into the Override (but not elsewhere since the other folders require authentication). Do you think the result is the same when I just run the installers and navigate to the package folder, or should I move it first and then run the patcher just to be sure?