YBBR:
-You're unable to open the mod menu after beating Stalk Yin second phase, potentially leading to a softlock if you had noclip enabled when the fight ended.
-You can't open the mod menu at Jonathan's house, in the Music Room, or in the Nulbo bossfight (first two are probably intentional but players should be able to undo their cheese settings after getting past Blabi via mod menu)
-Spawning and interacting with Cave Stalkyin via mod menu results in a softlock as the game tries and fails to play the cutscene you see in Main Mode
-The game still crashes in the Computer Ending even if crashing is disabled in Settings
-Indicators in Stalk Yin second phase appear after he moves
-Playing "Indignation of the Blab" in the Music Room causes the whole map to set on fire.
There's probably more mod menu bugs I haven't found yet, but at the moment this probably stands as one of the BEST debug modes I've seen in a Baldi fangame or mod and it's really fun to mess around and experiment with. I do wish there was an Invincibility option however.
FFS:
-Item audio in Outdoors doesn't loop
-Two posters seem to have missing textures, those being the hidden thank you message in Power of Friendship and the poster in the dead end hallway in Nightmare
-Every story mode level is possible on Hard Mode except for STOP level 2. Haven't tried every bonus level on hard mode yet though.