I got the number error when I wanted to create a new chain with 6 blocks per hour and 50 coins per block. On the old site it worked to just enter 50.0 and 6.0 instead. On the new site that doesn't seem to work.

Maybe it would be a good idea to have users pay "electricity fees" for their rigs. It makes things more realistic and it also solves the problem of everyone just buying a ton of rigs right from the beginning because you could make a loss if you aren't careful. If your balance reaches zero, all your rigs would automatically be turned off.