Revised suggestion after sleeping on it:

Immersive (re)building would definitely be sweet and intuitive and could probably be boiled down to a few mechanics:

1. Interacting with a wall with a decorative tent block should be like painting it to that block...

2. Interacting a door, trapdoor, glass block, ladder, scaffold, crossbeam or fence on the wall/floor/ceiling should open an inventory UI with info on what would be needed/returned to upgrade/downgrade that border in various supported ways.

3. Start all tents 3x3 (as if the walls were fabric thin), and expand as the user chooses through upgrades (higher tier crossbeams should offer the opportunity to magically get larger inside than outside).

4. Sneak interact to attach a decorative or other block (like with chest/oven/etc)...

5. On the outside of the tent, if any block is placed touching the tent itself, by a tent owner, while a tent block or item is in their offhand, it should be protected/picked up/replaced as part of the tent during setup and teardown.

6. Tents should start blank, but be copyable like maps, and re-nametag-able to break any copies/permissions.

7. Crafting blank tents to rotate copies of all you are tagged to (easy replacement for lost tents).

I love this little nomadic gem, although I just discovered it last night. Let me know how I could help. (Besides the obvious Patreon, and actually figuring out how to use gradle of course :P )