If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.
The poor OP probably only has one show slot left and he has narrowed it down to either Fun Home or On the 20th Century. Little did he know that he was unleashing the full joke potential of this board with his innocent request.
"I think what is being asked for here is a thorough breakdown of legal loopholes that would permit someone to see both."
I think they only check the names of the purchaser between box offices, and you don't have to include your guest names at that time. So, if person A buys two Fun Home tickets, and person B buys two On The 20th Century tickets, you should be fine. I would recommend doing that early in the run, in case they catch on, though.