Having a route that defaults to "Fixed" mode, or the ability to switch to Fixed mode on any route.
I'm an AppleTV user, and it would be nice if there was an option to ride a route that defaults to "Fixed" mode (all flat roads), which would be great for recovery rides, easy endurance spins, or even typical zone 2 rides ... when hills are not ideal.
As it is now, once I choose a route to ride, I have no means to switch to Fixed mode before or during the ride. I think many users would find this convenient when doing training rides that are best done on all flat roads.

Many thanks for your suggestion and support for TrainingPeaks Virtual.
You can already achieve this using the Trainer Settings options (available from Main Menu > Options > Trainer Settings). Simply change the gradient / slope feel to zero and all roads act as if they are flat.