Doing this, will directly lead you to the left switch, without triggering the boulder at all! After throwing all 3 switches, the boulders trigger will be deactivated, making you able to bypass it. Saved time is at around 30-40 secs. To get a good succesrate on this, you'll need 40 or less fps. Note: I later found out that if you don't trigger the boulder before activating the one switch in the main hall, this switch will be bugged and won't open the gate. To avoid this, you'll need to either kill Lara (after throwing the switch), which will magically open the gate after restarting from a checkpoint, or you just trigger the boulder shortly before performing this shortcut (recommended)! By jardart