I wouldn't use it or promote it.

• email infrastructure has been on the path to centralization for years, it's a cartel now in essence
• almost everyone uses the monopolists' email service

LNURL will probably end up unsupported anyway (lightning devs are coming up with a different standard), so using this protocol means supporting 2 other protocols that are on their way to obsolescence

I realize that there may not be any privacy problems depending on how it's implemented, but I'm still not interested; it's using a creaky centralized system that is otherwise on the way out