Nowt wrong with doing your revalidation in a group owned aircraft providing the instructor is not paid for it.
It's in similar vein to the nonsense that says that you can be taught to fly by a PPL FI with a Class 2 medical. However the exchange of spondulicks renders it a much more dangerous practice, requiring a CPL and a Class 1 (presumably to ensure the instructor does not have a heart attack while carrying the dosh to the bank). At least that one is being addressed.
FWIW LAA does not set the Permit Conditions, CAA does. CAA is the regulator, LAA is an approved organisation.