poison gas machine cutting off another machine

[MattWeiner]

On level 6 of seed 372419447, the southwest corner contains a poison gas/portcullis/lever machine and, behind it, a key across a lake of lava. If the poison gas machine is triggered first, the player has to go through poison gas in order to get the key in the lava. This seems contrary to the idea that machines shouldn't break the continuity of the level.

This problem could be solved (and IMO it would be better) if the poison gas from the portcullis/lever machines dissipated after a while. The gas could stay around long enough to kill a player who didn't find the lever or jump down the hole and then dissipate, so it wouldn't be a permanent obstacle in the level.

Can be seen at brogue.roguelikelike.com/#viewRecording/BROGUECEV140-66d5067b4f9d708fb29cb48a around turn 6000.