What is the difference between the workload of an author and the rights of use of this author
Workload of an author (or consultancy) is work. Just like any other. The author(s) should be paid for it as for any other work unless themselves choose not to (in case of sponsorships for example). The workload could be a simple idea, sentence or serious design research.
In the event that by client committed concepts, ideas or other author’s (or consultancy) work will not be used or performed or published, the client is not liable for the payment of copyright or rights of use.
The workload itself need to be paid as agreed in advance.