You seem pretty active with OSM, so I'll propose this here since I don't have time to make it.
OSM is very, very popular with hikers and cyclists, and I'd argue rhey drive a lot of it's use, especially via third-party systems. However, it's one failing is "gravel" roads. While they support many different gravel road types, they admit on their Wiki that use of the proper terms is low.
Given the heavy use of Garmin devices, especially among gravel cyclists, mountain bikers, and bikepackers, where terrain definition is important, it would be outstanding to have an app in the Garmin store for Edge devices that could report the exact terrain type (compacted, dirt, etc) with a button mash as you ride it.
Yea, I've used that, but it's a phone app. Riders need a one-touch solution on Garmin (or other bike computers, but Garmin dominates the market right now).
It also doesn't seem to let you edit anything more then a mile away from your physical location. I get that they want accuracy but it's preventing me from editing incorrect information to a place I have just been.
I already uninstalled it so can't confirm but I didn't see anything to that effect at the time. I could be wrong.
That said, I got Every Door and love it. It's got an icon right on the main screen to download whatever area you're looking at. The UI in general is more to my liking as a geek, whereas Street Complete sorta makes a game out of it (which is awesome if that's what you're after).
Not sure if you're the one to ask, but are there any good alternatives to Strava built on OSM? I don't need all the fitness analysis and social features, I just want to track my walk route and get basic info like miles traveled, elevation change, average speed, etc