Check their business offerings, the higher bandwidth plans from ISPs usually ship with a public static ip.

Few things which makes achieving reproducible/deterministic builds hard are - timestamps of generated/compiled files, continuously updating versions of build tools(+support libraries), output binary difference compiled across different OS.

We can use docker based build system for this, but it would require very carefully configured Dockerfile to keep the build tools+libraries on specific version. And if we do a pre-built Docker Image, then the Reproducibility of that Docker Image has to be proven first. It is indeed a difficult task, but not an impossible one. With F-Droid providing a sound framework for reproducible build generation, I believe we would have majority of large Android Apps reproducible in next few years.

+1 for recommending Fossify over ‘SimpleApps’

Extending the reply for ‘Sandboxed Play Store … F-Droid … Aurora Store’ -

1. In case of Sandboxed Play Store - we’d need to login via a Google account in order to be able to download apps. Also, when we allow network access to the Play Store, it may send device info, app downloaded, updated etc related telemetry to Google. Also expect the promoted apps/games ads in the Play Store home screen.
2. In case of Aurora Store - we can use it via Anonymous User or we can supply our own Google Account. Aurora Store just uses the credentials to download apps from Google Play, but other telemetry is limited compared to Play Store.
3. In case of F-Droid store - It mostly hosts open-source Apps. And has cautions whenever an app uses proprieray libraries, code or needs access to specific network(eg - Telegram FOSS needs Telegram Servers access to function) in order to work.

I’d recommend you have both - F-Droid and Aurora Store. If you need to access the Play Store subscriptions, then you’d need to install Play Store as well.