New "Keep velocity while Teleporting" fix not working properly

I was making a trampoline out of slime blocks, and was disappointed when I stopped bouncing. I tried to fix this using a tripwire grid across the whole thing connected to a command block set to teleport 5 blocks upwards. The end result had an extremely jerky performance, and sometimes lag teleports. Adding a delay to the command block does not fix it. Attached is a world download of the trampoline and the rest of the setup.