Integration with Relevanssi

I asked support about integration with native WP search (I had just purchased, didn't realize it required it's own search form...) here is the answer I got:

WP default search can't find files in the File Downloads plugin, it's related to file access restriction and other technical issue.

So then I asked about third party plugins like WPSearch or Relevanssi https://www.relevanssi.com which is when I was redirected to this feature request forum.

Needless to say it's important to me that:
1. The theme's search field can be used to search across all taxonomies, including file downloads. My sites have tons of files and search would be looked at as useless if it couldn't find files.

2. The ability to search across a multisite network is huge for the same reasons as above, which is possible with Relevanssi. Not, as far as I know, with WP File Download