I am not sure any H3 drivers have fuel puking issues. I do know XL coaches with dual side fills do have problems. The XL with single side fill has had no problems.

I think I have partially solved my puking fuel issue.

I have a truck stop near my house that has a big boy truck stop hose and nozzle on the RH side and a baby hose and nozzle on the LH side on one of the aisles. Since I have 298 gallons capacity I can almost always limit my fueling to that truck stop. I fill with both nozzles until I get close to being full, then I stop the big nozzle, and drop the flow rate on the baby nozzle and wait.

Eventually the bus gets full, but the baby nozzle does shut off without the puking.

As an alternative there is a Pilot convenient store also near my house that only has 3 truck bays for fueling. I have found on one of them I can use a big boy nozzle at the 1/3 open position when it is nearly full, and when it is full the nozzle clicks off. Then I count to three, and about a cup of fuel spits out, and most of that stays inside the fueling door area.

You may not even have a fuel spitting problem. But until you know for sure, stand way back, wear old shoes, and use gloves.