This is an example of a side road crossing I added. I think it gives enough information to a pedestrian router and in an imaginary situation (?) where you could tell a router "I'm in a wheelchair" it could slightly alter routes to avoid places where there are high kerbs.
https://www.openstreetmap.org/node/33965546
There are a small number of local residential roads where the sidewalk is only on one side or there are no sidewalks at all so I tag those, and I think that gives routers enough information to know where to tell pedestrians to go. (https://www.openstreetmap.org/way/165299914 and https://www.openstreetmap.org/way/5052147)
Sorry, long comments for a changeset, maybe I should have contributed to the Community Forum thread!