Agreed, I think more EASA OEB reports will be produced which may move the goal posts for initial TR too.
I suppose the above will have to be taken into account along with the minimum requirements set out in Part-FCL to end up with a course laid out in the ATO which is acceptable to relevant CAA.
I presume difference training must be an approved ATO course?
One last thing, does "should" = must? Or is it highly frowned upon if you don't?