So, this year you may have seen the expansion blockers which form a wall above the robot in the endgame. Would it be legal to create a wall which then basically smothers the opposing robot, preventing them from expansion?
As long as it follows all the rules regarding entanglement, you should be ok. An idea I saw was a wall on top of the robot and on both sides that come out and trap robots with expansion in the corner. If you do this, make sure all the rules with pinning are also followed.
Wrong category, but yes, to my understanding. Entanglement would be the main broken rule there I believe, which in endgame is overruled, so it would be as legal as any other expansion that went on top of another bot (string shooting over)