There's no way to create pbix programmatically, you can check this idea and vote it up.
By the way, what you're trying to do when saying "there is currently no way of easily updating all the reports built on one template".
There's no way to create pbix programmatically, you can check this idea and vote it up.
By the way, what you're trying to do when saying "there is currently no way of easily updating all the reports built on one template".