The uniquely scaling creatures in the cycling deck are the right tools to expose the holes in this metagame
You could also run cards like Inspiring Statuary, which lets your noncreature spells use your artifacts to help pay their cost
Also, keep a lookout for Rainbow-like energies (Rainbow, Blend, Aurora, Unit, etc.), which could allow you to mix typings more easily
I even considered both War Horn and Sunken City
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
Nowadays we are spoiled for choice in this area and have no need to look to the original