The Gen4 magazines have the cut-out to enable the ambidextrous magazine release. Other than that, the Gen4 magazines are identical to the Gen3 magazines.
I own several of each generation, and within caliber families, magazines are fully compatible in that you can use the longer ones in the shorter frames but not vice versa. Being right handed I've never repositioned the magazine release so they all work for me.
The thing about the model 36 being single stack is no other model's magazines will fit much less actually work in it.