[TechnoProdigy]

Staff are always keen on any machine that moves players using pistons ... make sure you plan on a heap of them in Techno Tower

I did briefly consider making a piston elevator, but then thought about the potential lag.

Anything with an infinite redstone loop that cannot be turned off isn't allowed. As for specific contraptions it would depend on what you were making I suppose.

I'm generally just going to make lots of doors, walls/floors which are actually secret doors, a few traps (labeled, of course ) here and there, and probably some other contraptions which I've yet to come up with. Most of the redstone contraptions will involve moving lots of blocks around, basically.

[Bu1ld0g]

Staff are always keen on any machine that moves players using pistons ... make sure you plan on a heap of them in Techno Tower

So not a good idea for use in an afk grinder?
*goes back to minecart idea*