MD83FO:
I once had a jetblue captain switch off the seatbelt sign during an hour taxi out so that pax could go to the toilet and crew serve some drinks.
what do you think about this kind of practice.
Not on the taxiway. Never.
Having said that if we were told to park it in the "run-up" for a long delay and engine shutdown was okay with ATC, then we would turn off the seat belt sign after explaining the situation to the pax.