I'm not a huge fan of modded machines. I mean, there are lots of beautiful modded machines out there, but when someone shows up in a multiverse server that is supposed to be "vanilla" with a 1000 power cannon, a negative power vacuum, or a bomb twice as large as the original one, it's kind of annoying. I wonder if it is possible to add a switch in the multiverse level setting to allow only vanilla blocks. It should be easy to implement (just check if the block size and block parameters are within limits). Modded players can still choose to play with modded machines by leaving the switch alone, and vanilla-purists can choose to limit modded machines.