[Grim Tuesday]

If they really did do it for the purpose of allowing teams to play 'real' practice matches (ie practice driving) then why not allow both on the field but not at the same time. Every other 15 minute slot could be tethered and teams can sign up for whichever one they want. Maybe to regulate it say that one of the flex slots must be in a driving practice and the other in a tethered practice.

I think that, on a 6 team field, there really are major safety issues. Full court shooting comes to mind. There would have to be safety regulations for the tethered field time where other people are on the field requiring hard hats and disallowing shooting from beyond x distance. Additionally, climbing and shooting could be difficult together: if one team wants to climb the back horizontal bars of the pyramid and the other wants to shoot from the back, they could intersect. To solve this, practice zones would have to be reserved and designed so that robots could not interfere with each other or endanger the people on the field.

Sure, lots of problems exist but they all seem solvable.