Since DS writes 12 updates a year, since "théoriticaly", half of the updates were for max, and the second half for Kate, the best is to have two games, where, Max can sometimes plays a rule in Kate's story and vice versa but no more.
With an update for each game every two months, I think it's the best.
The problem are the Patrons and I think the "Max-BB" lovers pay more than the others even if the rules (by vote) one year before were 50/50... And one game probably gains more than two separate games...