Crab,
"In order to recover the transfer pumps in the main tanks with fuel (which will after a while cancel the F pump caption even with the transfer pump switched off)" No it won't - Transfer pump OFF = Caption ON.
"which moves fuel from the supply tanks (the ones which feed the engines) to the main tanks through the overflow pipes."
No, it doesn't. It allows the fuel settled at the rear of the MAIN tank to slosh forward over the front transfer pump - which will clear the caption.
We are talking about a gentle nod - nothing aerobatic.