This doesn’t seem super safe from a security standpoint. Can anyone comment on safety?
Yeah fdroid is vastly preferred over this because you can be sure that the source code provided actually produces the executable.
F-Droid installs an APK that F-Droid compiled. Obtainium installs an APK that the app developer themselves compiled. I’m not sure what you’re getting at.
Malicious APKs, built by the developer themselves, not matching their public source code.
Which developer?

If you think about it, any developer could have their account hacked and the attacker upload an APK that includes malware. Obtainium isn’t doing any malware scan or building from source or anything. If you are planning to just install from GitHub anyway, Obtainium should be a no-brainer. But I can see where might argue that having a middleman like F-Droid to validate APK integrity has some merits.

f-droid.org/docs/Security_Model/

f-droid.org/docs/Reproducible_Builds/

apt.izzysoft.de/fdroid/index/info#security

Security Model | F-Droid - Free and Open Source Android App Repository

App signing Initial Installs F-Droid as built-in app store Protecting against malicious contributor-generated data HTTPS/TLS configuration Security Au...

Fair point. I guess it boils down to if you prefer speed of update (obtainium) or the extra checks f-droid has in place and if you continue to trust that f-droid’s stuff doesn’t get compromised.

It’s also worth mentioning f-droid’s workflow far from guarantees there’s nothing nefarious in a package. The bar looks to be passing virus total and then ensuring the provided apk matches source. If nobody reviews the source each time then every release could be the one that gets a nasty surprise.