Honestly, it would be nice for on certain maps every playthrough different pathways would be open or sometimes unavaliable. Like imagine if on Map 1 the wooden platform leading to the hole where you normally go through to get onto the roof would be broken occasionally, leading you to instead go through where the Level 3 keycard door used to be in the kitchen. Maybe rarely they'd both be open at the same time.
It'd add more replayability to maps with the different routes, heck maybe even in the LE you can set certain walls/doors to have a percent chance to become a keycard door.
I'm sorry if im possibly not wording this right, im tired but i hope i got my point across. Let me know what other/alt pathways you'd add to maps. 

