Permissions by Customer

We have a requirement where anyone that works on one of our customer projects must only be able to use it for the basic functionality, which is project, tasks and time reporting.

I can't achieve this with a profile as the staff working on this project will also be working on other projects, where they dont need to be restricted.

Therefore, it would be very useful, for us, if permissions could be set on a per customer basis.

Thanks

CR-254559