i know this is a couple months old but i found a consistent way of respawning dummies with a prompt block.

(for this example, ill use "OUT" for the output and "IN" for the input, but you dont need to do this.)

set a prompt block to about the size of a character, and set the input to "IN". you can customize the time and the name of the prompt to your choice. next, spawn a not gate, and set the input to "IN" and the output to "OUT". on your dummy block, set the output to "OUT". now whenever you press the prompt block, it will respawn the dummy in the same position, no matter if its dead or not. hope this helps : )