Portals and door gameplay

Can we and a channel on blues to end this fighting teams that just sit next to an escape and shoot at you please. and the door way combat is terrible you just wait and wait until finally a team runs or goes in and typically whoever goes through the door first loses (Im talking from a trios perspective). What kind of mechanic could we add to do away with this. I know you can destroy doors in numerous ways but that doesnt change the game plan wait for first person to enter body block them with a spell. Its just not fun gameplay imo.