That's a California thing, not a Harley problem. CA has the dumbest gas nozzles in the world. In most of the US you don't need those orange collars.
Michael, it's worse in Cali due to the evap emissions crap on the pumps, but it's also a problem in the rest of the country. It was somewhat of a problem on the 5 gallon tanks, but much worse when they changed to the 6 gallon. If you find a pump nozzle that allows you to throttle the flow way back, then neither is a big problem. Unfortunately, most pumps I've encountered over the past 10 years seem to have a hair trigger and don't allow for a slow flow. And when you run across those types of pumps, the design of the filler tube and high backbone in the tank conspire to cause splash back as the tank gets close to full. Shoving the nozzle further into the tank in the hopes that the auto shut off will kill flow before it splashes back might work, but then when you try to top it off by backing the nozzle out you still have to deal with the hair trigger problem.
In my old industry, we went through issues over the years with fuel filling complaints, either slow to fill (fast fill would kick out the pump prematurely), incomplete fill, splash back, or other issues. Unlike H-D, we spent the time and money to redesign things like filler pipes and tank venting systems to solve the problems. I don't see why H-D can't do the same, versus selling some cheap piece of plastic you have to carry with you (and store on the bike) to help solve
their problem. It never ceases to amaze me how Harley customers constantly and willingly put up with stuff that they would never accept from other companies.
Jerry