I do agree the door doesn't open fast enough. I couldn't tel what the other 4 were fighting so I unlocked the door. Noticed boss was already spawn. Tried running but was stuck at the door for a solid min even though it was clearing. Luckily it was a perfected dreg. It's not hard to get keys but I don't want to farm them. I learned my lesson to always check before I randomally drop a key.