yeah, great plan, trensidoh
I really hope you’ll work out a way to record one or both of the shows! 
I guess it’s like always: it would be cool with the band, but most of the venues say "no" when asked officially, but usually tend to look away when you carry in cameras or recording gear. in the worst case they would keep the things in a safe place for you until the show is over, I suppose.
but about the actual recording/photographing policy of the Forum I don’t know anything.