Thank you for your question, Mr. Bernier.
Under a publishing agreement, an author receives 10% of the copyright fees from the sale of a book. That should be the standard contract. Unfortunately, nothing in the Status of the Artist Act requires publishers to negotiate with writers. There is no collective agreement, so every case is handled differently by publishers.
As for copyright fees that are part of exceptions, the one related to fair dealing leaves much to the imagination and creativity of the two parties, but it is rarely to the benefit of writers.