To contribute to this topic. I belief this would be done with two spruces.
1st sprue would have two tiles on it. These would be dubble sided with onside detailed for floors, and the other side detailed for walls.
The 2nd sprue would be a Assessory sprue. It would have one set of Doors, and Assessories for your dungon. These would be torches for examples that you could glue to the walls.
Also I got a feeling alot of dungon masters out there would love some sort of creative "trap marker", to mark potential traps for there dungeon crawlers.
Each box should be able to make one hullway in any shape of the "Tetris" blocks.
This means a 4 squars of floor. So that would mean something along the lines of 6 of the main sprues, and 2 of the accessory spruces sound right. That would mean 8 sprues all together.
With alot of the $20 boxes having about 10-14 sprues in it, This would be a MUCH cheaper option compared to the many resin options on the market right now.