Ok after some talk with Random I settled on using a method wherein the game pastes every single tile into the level as a backdrop via the Active Picture object; it uses the create backdrop function to both create the graphic AND collision map across the entire level, a method that might require 10000 backdrop objects per level. However, these are just backdrops not actives, and while they are restricted by the active object cap, I haven't noticed any slowdown and the whole level generation doesn't take more than a second or two.
If anyone has a reason why this wouldn't work, best tell me now!