This is the full optimization of Dark route and Big room (single segment):

Compared to the best Dark route segments ever posted on the leaderboard, this new optimization can save 2 full piston cycles (over 20 seconds skip)... also, just for fun, I included the most optimal big room possible (in theory) and it could save up to 1 minute overall, when getting first try 1BoxPiston glitch (see the end of the video).