Well it turns out SSG patches their steam and windows installs differently. I tried to speed up the repair by using steam dat/datx files that have already been patched to 33.2.1. These steam dat/datx files are different from the ones installed into my working windows 11 box. Thanks SSG for non-deterministic dat/datx patching. That means two sets of hashes...because of course the steam ingame experience of LOTRO is different. I mean client_highres.dat is different because the textures and shaders are naturally different on steam vs. windows.

But yes, all this trouble because sometimes the patcher doesn't ask for admin. It only takes once and by the time you've noticed it's too late. Who knows maybe the game is supposed to ask for admin but doesn't. This is definitely relevant.