Not sure if someone else already figured this out but...
One thing a lot of people have complained about the Platform Behavior is that you can't do a sustained jump with events. Jumping with events also happens to be one of the only way to do double jumps, forcing alot of people to decide between it and being able to vary jump height.
Here's how you fix that...with just one event.
Shift: Behavior Built Jump (With Sustain)
Space: Event Coded Jump (With Sustain, can be fired multiple times)
Note: Construct 0.99.96