In short, there is no reporting or way to measure the impact / improvement a website has when we instrument Schema Mark Up. The promise of deeper Google indexation of content on webpages is something clients take our word for. The tag is served by Google Tag Manager so we just assume it helps with SEO indexation. But does it?
Here’s some more information about it https://developers.google.com/search/docs/advanced/structured-data/intro-structured-data as well.
Probably the most logical schema is theLocalBusiness Main location & LocalBusiness Per location Pages as this can be used to help store locations get better indexed in local results on Google, Bing, etc.