Currently it does not seem possible to rename a project (or change any other properties for that matter).
At least I am not seeing any PUT or PATCH endpoints.
This would be very helpful when creating projects from a template where the newly created project needs to be called something else.
I guess it is technically possible to do this by first creating a project from the template, then using the copy endpoint to specify the project title, but it seems a little cumbersome, and there is no delete endpoint to clean up the first project that was copied from (see https://www.taskade.com/feedback/public-api/p/delete-project).
An alternative (for my use case) would be if the from-template endpoint can take an optional projectTitle field.