The only one that know is obtainium, but from what i understood it only fetches the latest version of an app and it doesn't even check if it gets installed correctly.
I'm also i'm concerned about the safety of the apks; i know that trusting the f droid repo isn't any safer than trusting the builds from the dev, but it would be nice to know if there is any way to check other than checking the code by hand.
Keep in mind that other reputable repos like izzyondroid still work, fdroid is more then one thing. We wont loose the apps, nor the 3rd party repos, the only thing really "at risk" here is the official fdroid repos.
this isn't like some closed source stuff, the entire fdroid ecosystem is fully foss so anyone can sweep in at any time and do their own thing while still being mostly or completely compatible
And there's already a bunch of good alternative clients available. I like Droid-ify because it has support for using Shizuku for unattended auto updates when I'm on my home Wi-Fi.