I'm really sorry. It's sometimes hard for me to distinguish a purely theoretical, but DRLA-related, question and an offtopic question. All that Use bindings etc are assumed to be DRLA compatible.especially when the project author has already told you to quit it
Zdoom jump can't always compensate player speeds lower that vanilla. It works on rifts with same height, but it sometimes can't work with cliffs. There are always some workarounds. You can implement a sprint option which allows to run with vanilla speed for limited time, and then lowers the speed or even begins to damage player's health. And, speaking about the „Using empty spaces“ event detection (this time it's definitely not an offtopic): if it's possible with Decorate, it can help to avoid binding a new key. Run + Use + nothing to actually use = Sprint. So no additional buttons will make acrobatic jumps even more difficult.
Spoiler: