Hey, not sure if you did any more with this, but I'm modifying the dashboard for my GMC.
Initially I didn't get any fuel info either, but when I entered my fuel tank size in my vehicle setup, then it started showing me data. Because it's a calculated field, the DTE number isn't accurate, but should adjust with time as it gets a better average mpg value to work with (at least that's what I've seen with other dashboards).
I also had to adjust some needle scales (like torque and power) that didn't have good ranges on them.
I'm still not getting fuel rail pressure data. Haven't dug into that yet.
Thanks for your work on this.