Rule <SG12> states that “Robots may not interfere with the raising of the Gate, nor may they lift the Gate.” However, if the gate is lifted before the 35-second cutoff, could a robot feasibly legally lower it? <SG11> says that the gate cannot be dropped, but it doesn’t specify by whom, so that may just answer the question.
Also, would it be legal if, say red alliance has the bottom piece in a goal, blue somehow lifts the piece within the goal , and somehow inserts a blue piece underneath the red piece so that when everything is released, the blue piece is now the lowest, and thus recieving the bonus?
No, once the Gate it cannot be dropped. This means the Gate cannot be returned to a down position by any means. This rule will be strictly enforced in the interest of safety of all robots and team members.
Please see the updated version of the <SG9>, quoted below for your convenience.
So, once an object is Scored under clause 1, meaning it’s fully below the top of the PVC pipes, it cannot have its value altered. So the maneuver you described would not be legal.