This is absolutely wonderful.
I was about to give up on Rpg Maker and just happened to spot this plugin. It's by far the best jump system ever created for this engine. Anyone who decides to use it should try pairing it with the MV3D/MZ3D plugin as their combination is seamless and in case you desire to make a platformer in the style of games such as Crash Bandicoot, you can do so very easily.
My only suggestion is the implementation of the double jump.
Amazing job.