In the top post? Looks correct to me, links to v4. Github's latest release link takes a little bit to update maybe. Updated the v3 release post just in case as well.
I don't really know what the issue is here, but you can try installing OpenMW 0.46.0 instead of the latest version, since that is what the Switch port is based on. You can also try copying Morrowind files directly, like the second block of...
Interiors look pretty normal to me. Though I haven't played Morrowind in a while.
You're right about the Y button, though. The issue is probably me fucking up the SDL button remapping. I'll push a fix in a bit.
Edit: Uploaded the fix for that...
Recompiled: link
This should work on newest firmware versions, though I haven't updated past 18.1.0, so I can't exactly test. It does work at least on that FW version, though.
Also increases the deadzone a bit because my sticks are a lot more...