In theory

[Southern Gothic]

If SSJB Vegeta got hit with the Blutz waves, would he become an SSJ4? Or Goku for that matter? I don't see why not, unless I am missing something.

 

[SSJ2]

They would still need a tail.

Maybe. They might become something else entirely, or nothing at all.

 

[Southern Gothic]

Vegeta had no tail from the Blutz waves. It just...grew. I imagine a blue ape to be honest. Or red. Because then the ape would have to first master SSJG and fuse it with Golden Oozaru and my brain hurts now.