Compromise Gents and ask for a 5 or 6 hour time limit.
Would we like 2 LW Arenas with Caps put back in?
I do remember side switchers that would try to Game the Game. Not many but enough to ruin fights for others. I often avoid areas of uneven Dar Bars unless it's more Red. Upping against the odds is the fun of a game with no real consequences.
For the OP: If you just logged in and wanted to switch YOU CAN. You just can't switch back right away, make your decision carefully. 
6 hours would not be awful, but not as good as 2 hours (even tough I prefer 1 hour)
12 hours is the same as 24 to me, with a possible exception for the weekends.
If I switch at 6PM, local time, that means that I cannot switch until 6AM the next morning by which time, I am leaving for work and obviously cannot play until I get home at 6PM that evening, effectively making it a 24 hour side switch for me. I cannot imagine that there are ot a lot of folks in the same position that I am with regard to having a job and not being able to play during most weekday hours.