The uniquely scaling creatures in the cycling deck are the right tools to expose the holes in this metagame
First, it affects multiple creatures, which forces your opponent to pump everything or wave goodbye to their undefended Hierarchs/Elves lying around
Another potential rubberbanding cause is a poor internet connection
However, effects that stop a creature from untapping "during your untap step" or "during its controller's untap step" won't stop that creature from untapping during another player's untap step, and as such, Prop Room's ability will cause that creature to untap
Also, keep a lookout for Rainbow-like energies (Rainbow, Blend, Aurora, Unit, etc.), which could allow you to mix typings more easily