Why wouldn’t you just ask them? Say you have included service on the bill already!
I know I could do this, and I did this time, but I felt a bit mean doing it. I always have thought of myself as being a good tipper and to put £0 when the machine is presented to me with a box for "tip" just jars.
I do wonder if I should take cash next time and then leave a cash tip.
I had heard about this at some much posher West End places but this was Meghans at the Power Station.
Thanks everyone.