Life is definitely better.
Buying the replacement BMW K100 instrument cluster was much easier and cheaper for me than trying to figure out how to repair the original.
I haven't yet seen any evidence the newer cluster I have has a different fuel level light controller than the original cluster it replaced. They, externally and visually, are interchangeable. The round pins, to my surprise, make adequate contact with my flat pin receptacle.
The electronic fuel level light is, I have been told, a modern labor-saving upgrade to the archaic standard/reserve petcock fuel valve installed in duplicate on the few Airheads I own, whose fuel level is, as is here recommended for my K100, arithmetically deduced with the aid of the odometer.
Installation of external pump and filter and standard/reserve petcock Airhead-style to a 1985 K100 would seem to simplify this whole mess? I see the most difficult step to be sourcing a petcock bushing for the fuel level sender port.
I have experienced the fuel heating and boiling events firsthand.
Thanks for the search terms.