In Arnold Hague's book "The Allied Convoy System 1939 - 1945" (published in 2000) he has separate chapters on MAC ships and refuelling at sea.
He states "...It is worthy of note, in the present era of 'one-stop', extremely expensive replenishment vessels, that in 1943 it was quite usual for a tanker-MAC ship to operate three A/S aircraft from a crude flight deck with no hanger facilities; to refuel escorts and to carry spare depth charges. All of this was incidental to the delivery of a commercial cargo of liquid fuel. Indeed the reports of the Air Staff Officer of several MAC ships make it clear that it was not unknown for aircraft to be flown off during a refuelling operation..."
He reproduces a photograph of a tanker MAC - the MACOMA - refuelling a ship at sea; she also has four Swordfish on deck, and the hose streams out from the flight deck on the starboard side aft. She has a flag hoist, but they cannot be seen in detail. The caption says that it was probably taken during convoy SC168 or SC175 and continues "...the fuelling hose can be seen led over the flight deck aft of the deck park. This of course means that the hose passes over the arrester wires and, on its way from a forward fuelling point, obstructs the narrow flight deck. Despite this there are records of take-offs in this dangerous situation.."