One thing about an extra charge, if it is needed and every
dealership applied it, ie sanctioned by Gov UK, is that if things every settle back down, it would be removed by again Gov UK decree - if it was rolled into the service price and that jacked up, it would stay for ever.
My older daughter got her
Cupra serviced by AC in Edinburgh, originally all good "only collect and drop off and no wash and vac" when checking up as the booked time got closer, "only drop off - hire car might be available" - so she ended up booking a hire car, the very small one, no "wash and vac" which was understandable and the option she preferred, and no extra charging - that service was a pre-paid SEAT or AC service plan activity.
Edit:- also, I handed my wife's 2015 Polo into ATS for a cheapie AC recharge (it needed it) and they clearly laid down the ground rules as regards how they expected the car to be presented to them prior to them working on it, AC controls switched OFF, all windows opened before leaving the car, and I think clearly described, at the branch what they would be doing to minimise risk to us on its return - again no extra charge.