Our 2020 tin top run out model has the old gas still none the wiser on the mog or the amount it takes which is critical. A phone call to the service dept is the way to go.
When I maintained the fridge and freezer on my yacht in the Caribbean the kit I bought just required I re-filled, from a gas bottle of R134a I carried on board, to a particular pressure when necessary. I recall flushing through once or twice as well.
