It is possible to skip the activation of the switch for the Skittergate by using the terrain and Siennas firewalk ability.
How To:
Step 1: Jump onto the wooden beam and follow it to the left
Step 2: Jump from the beam sticking out to this location.
Step 3: Use firewalk to move as far as possible
Step 4: Use firewalk to this location.
Step 5: get up on one of the beams sticking up with the firewalk skill.
Step 6: Firewalk down to the ground on the left side of the switch.
Result: You are now in the area after the switch without activating it, and the gate is not active.
If done the correct way it is possible to repeat with 100% success.
pps. Arvid has seen parts of this already