Templating is about the structure of course shells before teachers add content.
Use of Blueprints is a possibility - and syncing is controlled by whoever has permissions for the blueprint not by the teacher(s) of courses associated with the Blueprint. Blueprints also allow certain restrictions on what course teachers can change. It probably makes most sense to set up blueprints in advance of teacher access to courses.
One consideration with both blueprints and templates is repeated use when teachers are importing from courses already based on blueprints or templates - this can lead to cumulative duplication of items.
Canvas Commons as @CelestialDawnA suggests is a useful and simple approach but does require action by teachers
Another approach would be to use the Canvas API. With the API you can change settings, add pages, standardize the course navigation menus etc. This can be done at any stage in the course lifecycle. If your new to using the API and/or coding try asking an AI to create code and test this thoroughly in a Beta or Test instance on sample courses. Have someone who knows the language (python, javascript etc) well check the code. Changes made via API are not generally locked down.