Dont put GAS in your M2! (Sorry I couldnt resist
But in all seriousness I havent seen much issue. I usually stop at double pumps so I can pump both sides at the same time. I pretty reliably get about 25 gal per quarter tank showing on the gauge.
Now that's all after the drive home when I stopped twice without realizing the transfer pump only runs when the unit is on. Took me a little while to figure out why I was only get 3/4 tank each fillup...