After testing for a while I think there's some serious bug(s) about part and door connection.
This whole matter has been a problem from the beginning so I'll extensively explain it again in detail and andress the current problem.
The problem affects parts that do merge in the same way corridors do.
In order to do that the parts have to set IsWalled = false
and GeneratorRequiresDoor = false
so there would be no walls, and hence, no doors require between each other.
The bug now is this causes them not to have doors when connected to anything else.
The problem with the above stettings is that although they are not set to merge or blend with vanilla corridors, they still are because there's no wall.
To have them require doors between them and corridors IsExternal = true
has to be set. Now this causes the current new problem (wasn't before) that they can't have doors with structures.
So they now have to be set properly with IsExternal = false
.
With this the current bug is they all need to define AllowedDoorLocations
even if there are no directional restrictions.
And we are back to the problem that they are not separated from corridors even though they are not set to blend with corridors.
I think it's time to clarify and or adjust the mechanics and rules how this works because now it's not working as supposed to in either cases with corridors or structures. This makes it a building bug.
Frankly, this problem is urgent for the Abh mod.