Not sure if I'm correctly referencing some things but I'll explain it better and hopefully that clears everything up.

Problem: Players can use creative split to their advantage in survival.
There are few ways one can do that so I'll list them because that will probably be better to read than my ramblings that tend to span on 10 pages:

• Ender Chest smuggling
• Filling Hunger points in Creative split (it just takes a little longer to eat stuff on Creative split but it still goes through)
• Potion effects transfer from creative split to survival split

Ender chest smuggling, all you need for that one is to just place a ender chest, put something in it, open it in survival split and there are items that you put in creative split there. Probably just disallowing placing ender chests or interacting with them should be enough to fix this.

You can eat in Creative split which would be generally fine but the hunger transfers along with you into Creative split so you can go to Creative split, hold m2 for a bit till you manage to eat and then go back to Survival split and bam, you're well-fed.

Potion effects, same deal as hunger though it's simpler since you can just go to creative split, splash or drink a potion, cross back to survival again and you get to keep the status effects (which I think there should be a config option to clear them after crossing back to survival split)

btw great mod, I actually really wanted something like this for a long time so I'm really enjoying playing around with it!