Thanks for the suggestion - Im thinking of features for the upcoming update, so I may add something similar if it makes sense :). One suggestion, make sure you tick “Override Z” on Launch Character so Mario stops going up immediate and slams down!
As far as the animations, Im using the standard Epic jumping animation, so not sure whats going on there. If your character is floating while standing, look at the size of the collision capsule for the CharacterBP and adjust the size so the character’s feet are on the ground.