AFAIK, the proposals are for nosewheel installation, where there are no brakes.
This now becomes a joke! Like those 2 dinky nosewheel tyres (on anything, even a 747) are going to have enough traction? Even pushback tugs with oversize tyres and weighing anything up to 20 tons or more can be slipping and sliding. And when wet- no traction at all! You would still need investment in all the pushback tugs (and their groundstaff) for windy or wet days.
It's a joke. It won't work. It's those bloody greens again. Don't listen to them.