Hi! I was messing with my friends and I came across this.
If you are flying with elytra and kill yourself via commands, you can respawn but you will be sorta flying.
You can do 2-3 block high bunny hops, fly a bit and can move REALY slow on ground.
You are even in the view of flying and can't use boost fireworks!
You don't even need the elytra after doing the glitch!