I might be repeating myself here, but consensus about tagging changes is not going to happen any time soon. My summary:
- Documenting the range of current usage helps mappers and data users.
- A sort of crude major subtype system using a subtag such as path=* with archetype pictures would help mappers and data users.
- Adding a usability or difficulty scale subtag might help
- Lifting one or two very specific subtypes out of the range could have a chance of successs
- Physical descriptive subtags are available, but (overly?) demanding for mappers and data users.
All of the above will not add up to 100% clear path mapping; there still will be many bare highway=path objects in the foreseeable future. So data users will still need to apply fallback values and fallback rendering.
I think it is worth it to appoint the subtype with the highest occurrence as the default type, thereby setting recommended fallback values for all relevant subtags. Not as a definition of what a path is, but as an anchor point for mappers and data users.
If a mapper knows how a bare highway=path will be interpreted, (s)he will be encouraged to verify and map the differences. I know I would.