I used Epefanes a Dutch Company that specializes in marine varnish.
https://www.epifanes.com/page/clear-finishes
I used it exactly how they said and even used their thinner. Only time will tell how it will hold up. However other than the sun my truck is not a good example as it isn't a work truck.
I considered Killer Bee's idea/product but cost won the day. We shall see if my usual less expensive do it twice history plays out.