Difficulties with filling the tank all the way up

I eliminated this on my 66’ by adding a vent nipple and a roll over valve at the top of the tank. You still can not walk away while filling the tank. But “splash down the side” happens about almost never since.

Side note: I bought a brand new tank to weld the vent nipple on and at the same time, I welded a tank drain in. For draining this ethanol crap out at the end of the year before hibernation. Tank welding can be very dangerous- fumes can linger and expand for a long time.
Syleng1