So with global confirmed its very posible that fuel burn comes with it. Instead of just select the fuel that you want in setting I have another idea.
This idea would consist in have a buttom like the pushback one you would have one that says START REFUELING. Once you press it the aircraft would start refueling and you would stop it when you have the fuel you want.
The fuel you have would appear in another page called systems and it could also be added an option to dump fuel in case you need it.
Comment what do you think of this.