There is no way to add GA Tracking Params. To be honest, I don’t think it would be very useful because Google can’t track Downloads even with those Params. The only way to add GA compatibility would be to programmatically use GA API and notify GA about every download when it happens.
I am aware of the utm parameters and their usefulness. The issue in this specific use case lies in exactly what you quoted (note emphasis):
“With Events, you can track interactions with elements embedded in your pages and screens, like buttons, links, videos, and gadgets.”
Download links are (mostly) not embedded in your pages, which is required for GA to be able to track them. You add a script snippet to your website so GA can track clicks. However, podcast episodes are (mostly) downloaded via RSS Feeds where GA tracking does not work. It is a technical limitation.
Podcasting relies on RSS feeds to work and there is nothing we can (and, in my opinion, should) do about it. It’s an established standard that allows podcast clients on any platform to read your podcast feed and present your podcast to listeners.
It is of course your choice to knowingly work around that standard and only publish your podcast on your website, forcing listeners to download/listen there instead of in their favourite podcasting app. Then you have a “Google Analytics” friendly, but Listener-hostile setup.
This will not work. enclosures in feeds must be downloadable entities, not html websites.
As I said before, the only way to add GA compatibility would be to programmatically use GA API in PHP.