We've noticed where ProductController.GoogleProductSchema() is generating up to 100 structured data items in a rich snippet array for products with variants. Our code coverage analysis shows this widget alone is responsible for 43% of the page postback speed when a variant dropdown selection is made.

I can't find any documentation online that specifically mentions a 100 element limit. Nor can I find anything that suggests having 100 elements actually helps anything.

We're scared to death to touch anything with structured data as it could easily impact organic SEO. However we're frustrated with the postback delays during variant dropdown selections.

Was there a specific technical reason for a 100 element limit?

I'm not entirely sure, but I think the widget tries to build every variant possibility regardless of the actual variant choices at a given time. And then stops at 100 for a maximum.

Is there a way to only do that one time on initial page load, rather than on every single postback? That's the problem - those rich snippets are getting generated every single postback and on a large variant matrix (6 option dropdowns, thousands of choices) it bogs down the page pretty badly.