Is there a good way of collecting information on currently missing Language / API calls in pages or files that have Flash elements not presently supported by Ruffle? It might make it more useful to know what makes one off well loved flash items not currently work, or which elements are commonly used but missing support.
There is a compatability page on the project website
https://ruffle.rs/compatibility
Edit: Rereading your question, I think you probably meant to see what is missing in a specific swf. That would be quite nice.