When I am reading Contextual Abstractions at whole I think it is very good step forword.
I like separation from usual function arguments. It make using library with context bounds much more readable. (I think context bounds is the main feature which should be known by library users)
I like the most things except one:
- Implied Imports
When I think that someone should sometimes use that it seems terrible.
It means that every usage of that import leads a question to google in the best case.
I have only one question how I can easy get rid of the need to use Implied Imports, when I solve libraries integration tasks.
It seems there are no such tools in scala 
I do not know the appropriate suggestion. But I think the answer is in scope management.
For example: https://kotlinlang.org/docs/reference/scope-functions.html