Hi Michael.

I've tested it a couple of times.

I can say that for cruise it is very accurate.  ;) Tested al FL310 and FL350.

For descent, at N1 55% mantain aprox. 280 Nm at 2000 VS.  ;)

For climb, it is complicated, because it depends on VS.
What is your climb rate?
For me, I try to be at speed:300 with a VS of 2000 - 2500
I couldn't get that with the model. I get speed:290 with VS between 500 and 1000 which is very low.

Fuel: I haven't seen that.

Great work!!!!  :)