Looking better every time you post an update, friend! I like your idea for doors, and can see how they could be used! My only worry would be how the addition of a tile less than a 5' square would change how the tiles would line up. For example: take the round room you provided in the previous post, and make the south hall the entrance/exit. If I build on the east and north exits with the desire that they later on meet, if one path has more doors, portcullis, walls, etc. than the other before they meet there will be a gap between the two paths. A way to fix this would be to use 'door' tiles as the connectors between rolled areas (halls, rooms, etc.). This can be done by including a tile for 5' and 10' offshoots that is simply blank. If you want to go a step further, you make all of the halls and rooms have a male connector end, and the doors a female, requiring them to be used. That may be a bit overkill and focused too much on the physical side of things, however, you might be able to set it up so VTT requires these door or transition segments to follow the room/halls (please note that I have no experience with VTT or any other digital battle map system). In conclusion, I find your work continues to show positive progression, and look forward to that which is to come.