Is there a mechanism under EASA for the UK CAA to make it a requirement under a variation for 60 AoB turns and practice collision avoidance
Don't forget, what is stated in the AMCs, GM and Part FCL are the minimum requirements. Each course COULD contain more stringent requirements should the training provider write it into the approved course documentation. So long as you include all the bits stated there is no reason whatsoever for the CA to reject either the course design or any application for licence issue which completed that course.
Sadly though, there aren't that many ATO's that would design a 60hour PPL course!