Ok gang, this one is way out of the box by my thinking but you never know, the good gents and gals at Adventure may already be working on this.
A couple years ago I added fuel flow and totalization to my Arrow (JPI). I liked knowing rather accurately, how much fuel I had left on board, and how much I had used. The issue that became aparant is that I only knew how much total fuel I had but no method of tracking the fuel remaining in each tank. I put a fuel card together to take care of that detail. By knowing how much fuel I had in each tank i could subtract fuel burn and keep track of fuel remaining. This way I knew how long I should be able to fly till approaching a dry tank.
the math is not that fifficult and I am pretty sure there are quite a few of us with fuel totalization and no way of knpwing what is in each tank.
As I said this is way out of the box but would be a great tool to have.