GPS tech (Garmin, Hammerhead, Wahoo, RWGPS, etc)

For the "climbing scale" this is what Wahoo claims... quoting from the mailing list

ELEMNT Climb/Elevation page scale
Normal Mode: 2km/2mi, y=200m/600ft ---> Fit All
Route Mode: 2km/2mi -> Fit Soon (20km/20mi) -> Fit Remaining - > Fit All (including History)

Normal mode is when you don't have a route (nothing is anticipated)
Route mode is when you have a route you are following so it knows what the profile ahead looks like

The scale is for the entire screen width (you can infer from the vertical has lines).

The -> means you zoom in, then loop around. It took me a few minutes to wrap my head around this, but it does make sense to me anyway.