What do you think about activating/deactivating groups? Not elegant in terms of number of events/lines but super simple and easy to maintain.
Got digger gear? Disable the normal duck movement group and enable the digger variant group.
Got the double jump? Enable that sub section of the jump folder that allows for it.. or for simplicity just disable the normal jump group and enable the double jump group.
Your character is any combination of enabled and disabled groups/behaviours this way.
I have no idea how this compares in terms of performance but I would imagine it would work fairly well.