Hi @Nat12 , if you are on an Enterprise tier, you can leverage the Bundles feature which will allow you to easily manage task templates across numerous projects (as well as custom fields, rules and sections to drive consistency and standardization). You can read more about Enterprise, here.
If you aren’t on Enterprise, then you could have all your Task templates in just the master project which can be used to create all tasks. Then you could multi-home the newly created tasks into the relevant client projects (add task to more than one project, or move them from one to the other). i.e. do not create any tasks in the ongoing service client projects (which would not include any task templates).
If you require any on-demand online support, feel free to DM me.