Is there a way to query all "Active Subscriptions" across a tag provider?

I'm doing a tag review and I have found the Tag Diagnostics -> Active Subscriptions page which makes me think that I can programmatically find all of the tags that are no longer being used, but I don't want to have to right click -> tag diagnostics -> active subscriptions every single tag.

I know this is a relatively new feature but I can't find any scripting reference for it yet. I have enabled the tag reference tracking in the gateway tag providers settings, and I know this will likely miss "ad hoc" references made via expression / script, but it can get me a shorter list of things to evaluate.

Awesome thank you!

wow that's way nicer than my recommendation
which was going to be manually traversing the tag source tree of every project and building a liveness graph