With more variations of fuels available, it is becoming increasingly difficult to plan a flight when you need to refuel. I think it would be interesting to see on the map which airports support the fuel type(s) of your selected plane, e.g. with airports that have your fuel(s) in a different colour than those that don't have your fuel(s). You could then check out those airfields for the exact fuel, opening time etc for your route plan.
I understand there are many different fuel variants and it's not all indicated in AIP. Would this detailed information something the users can optionally supply in a remark along with the price in airfield feedback?
I think it is currently not possible to indicate there that a fuel is not (anymore) available. Availability info is more important than the exact price. I am missing UL94 in the fuel list for airfield feedback, this fuel appears to be gaining popularity.