How do I amend roles for the Administer Users by Role module?
A possible scenario to implement what you're looking for is like so:


Use the Flag module to allow a Publisher (any other roles also?) to flag users to indicate that they "want to amend the role for that user" (say you label such flag as "Amend User").
Then use the Rules module to react to (Rules Event) "A user gets flagged with the Amend User flag", combined with a Rules Action to "grant a role to the flagged user" (which could be multiple roles also if needed).
If you need more granularity to be able to do so for multiple roles (like role A for user X, role B for user Y and role A and B for user Z), then just use multiple flags (1 for each role individually).


True, this would require 2 more modules, but pretty sure you'll find lots of other use-cases for these amazing modules (which should be part of pretty much every Drupal site).