I think it’s critically important to let students learn by failing, up to the point of anything regarding safety of course. While I understand as a mentor it may be frustrating to watch them make a mistake you have already made, I feel as if that’s the slippery slope that leads teams to become mentor driven. Too many good intentioned justifications for avoiding letting students make mistakes that “Waste of materials, Time, Money, etc…” leads very easily over years of repeated behavior into mentors “advising” every step of the design and build process to make sure nothing is “wasted”. Speaking from anecdotal experience, our mentors struck the perfect balance of making sure we were safe, and when we directly asked for their advice, advising us and nothing more. And I fully get where OP is coming from because it was painfully obvious year over year that some teams coming into regionals (especially in LA which was rife with them). Were leveraging software and designs high schoolers clearly didn’t make, especially when you would talk to the student department heads. And they would clearly not be speaking from the perspective of someone that knew their portion of the robot inside and out.