The fuel level indicator on the ST1300 may not provide a linear reading that reflects the actual fuel level, but I've always used the trip odometer to inform myself of the fuel range remaining rather than the fuel gauge. In fact I don't recall my first motorcycles having a fuel gauge. Taking into account riding conditions, solo vs two-up, headwind vs tailwind, etc. I can estimate closely enough how far I can go before looking for a a gas station. On longer trips I have my fuel stops planned to coincide with meal stops, rest stops, etc. And for the ST I take others' recommendations about not exposing the fuel pump seriously.
We all have different expectations from our motorcycles and I respect someone's need to change the way their bike works if it doesn't meet their needs. Good luck with your quest.