The idea of breakable doors is a good and dangerous one, the problem with this idea is the balance, as it stands most of the SCP's are somewhat balanced and capable of killing large groups of people, though each SCP has it's respective weakness and downfall, some more than others. If the addition of breakable doors were to be added there would need to be a large change in Meta, which the players can do themselves. My one big concern is the health of the doors, and which ones will be breakable, my suggestion is to give doors different HP based on type and area, as in the doors located in Heavy Containment being the hardest to break, and the doors in the Entrance Zone being easiest. The idea behind my reasoning is the current MTF Strategy is to go solo and run&gun all your troubles away after rushing the armory. This change would effectively allow SCP's to destroy the one safeguard of this playstyle, Doors. As the SCP's and MTF fight it out the SCP's could break doors along the way, which depending on situation could be a downfall or a saving grace, considering some SCP's use doors to deter rushing.