additional users triggering a new build without having access to the project?

Is there a way to give a contractor the ability to modify a scriptable object and trigger a build without giving access to the entire project?

 

The short answer is that yes, there is a way. You'll want to look into automated build servers, or "continuous integration" systems, and set one up with a relevant trigger and actions, which may require integration with other tools. It's probably somewhat of an advanced topic.

 

Setup an auto build branch on Unity Cloud Build and then whenever they push to that branch itll trigger a build