Yeah, Cali gas tax sucks! No other way to say it, it just sucks!

On your Harley, doesn't it have a quarter turn shutoff valve in the line from the tank? If not I'd put one in, and consider shutting it off and running the carbs dry after your ride when you know it's gonna be a while until the next one.... Doesn't help your tank liner issue, but keeps from gunking up carbs.