M wrote:

Ok, I have to admit, for me to plan a flight with 30 minute fuel
reserve, I have to start with full tanks. Otherwise there're just too
many variables to do it safely.

Even with full tanks, there are too many variables to really fly down to
30 minutes left. Just being a little off level when you fill your tanks
can make enough difference to make 30 minutes dicey in a plane that
burns less than 6 gallons in 30 minutes. That isn't much margin.

Matt