Would disengagement costing movement but forcing a character to take a movement penalty be a good compromise? Larian seems to feel that disengagement costing a full action is too harsh for a video game, but *some* cost is obviously correct.
Personally I find that the 'cheesiest' aspect of the current disengagement system is that you can jump right through other characters and enemies, with the way projectiles check for trajectory I doubt it's even a technical limitation. My suggestion for this would be turning 'jump' into a 'dive' of sorts when you are within melee range of an enemy with AoO, allowing you to spend your bonus action to basically fall or roll in a direction to avoid the AoO but not being able to get straight through enemies by doing so. Maybe certain classes like rogue can still be allowed to perform a jump in combat since it fits their MO. Maybe you could have a roll at the end of the 'dive' to see how well it went and how far you get to move after.
Another thing I find ridiculous is how far the push goes. It's more of a launch than a shove, sending characters that are nowhere near a ledge flying over the edge like shot from a cannon. Whilst I do find it fun to knock characters off cliffs like they're home runs, it is honestly ridiculous how far away you can pull it off from. I do hope they make the ledge falls a bit more reliant on ledge proximity rather than just having to be at an elevated location.