OpenStreetMap does have a key to store the incline of a road segment:
But, there are then two issues:
1) Does OSMAnd consume, and store, the value of this tag in its map
files? On this question I do not know the answer. But if the
answer turns out to be no, then there would be no way to use OSMAnd
to find steep roads. At least not until it was modified by the
developers to include this data.
2) Are any of your nearby roads tagged with the incline key in
OpenStreetMap? If the answer here is no, then it is not possible
for this data to be in OSMAnd, assuming OSMAnd does add it to its
maps. You (or someone) would first have to add it to OpenStreetMap.
My best idea for you to see if OpenStreetMap even has the incline tag
for your local roads would be to run some queries in Overpass Turbo:
This will let you query the raw OpenStreetMap data, and you can use it
to determine if any of your local streets even have an "incline" tag,
and if so, you can use it to find local streets with particular