Yep, that looks like it's the rotation bug. Once the PR has been merged I'll explain how to fix it. You'll probably have to rotate them into the correct position by hand and then export again. It looks very 'game-breaking' but once the code is in place, it should never rear it's ugly head again.
The easiest way is to rename the block filename to one of the existing ones, for example M000005.RDB.json and copy that file over to the World Data folder in StreamingAssets. Then just visit a location that has that dungeon block assigned. You will probably want to drop a start marker in there or it won't work. It doesn't need to be near a door, you can place it anywhere.
RdbObjectList just comes from the Daggerfall data structure: https://en.uesp.net/wiki/Daggerfall_Mod ... ck_Records. They are not special in any way, not sorted either, you'll find flats and models happily together in the same list.