Err...no. With both pumps off in the cruise, the contents of the Supply Tanks start reducing with approximately 250kgs left in the Main Tank, rendering that unusable unless you raise the nose to spill it through the overflow channels.
Yes, but when main tank is full or nearly full(ok I said plenty), the fuel in the main tank overflows into supply tanks, so transfer pumps are not needed, so they could be switched off. That's what I meant to say.