There is the “allow background usage” and “optimize”, but also, locking the app on the app switcher is supposed to help it stay alive.

Depends on Android flavor too. OnePlus OxygenOS, for example, does not respect the “do not optimize/sleep” setting, and will not let apps run in the background (or foreground) unless the app is in the invisible whitelist. E.g: WhatsApp is fine, but SimpleX is not.

https://dontkillmyapp.com/

You cannot use Proton Mail with another provider. And you cannot access Proton Mail from a regular email client (app) due to their encryption setup. (technically you can, but you need Proton Bridge proxy)

The bottom button was on LineageOS 14-15 (Android 7-8 equivalent… So rather old now)

GrapheneOS has it on the very left (as shown above), which requires scrolling, modern Samsung and IIRC older LineageOS has it on the bottom, always visible.

Samsung Galaxy S5 checks all of these. I prefer it with Lineage 14 (Android 7), but ran it with Android 8, and it can support up to Android 10 or 11 IIRC, although later versions are somewhat slow.

Samsung Galaxy J7 (2015) might also fit the criteria, even though it’s not a “flagship”.

If you’re looking for alternate OS list for smartphones and tablets, I compiled a list.

What’s your usage pattern for those devices? Almost full discharge + fast charge?

Asking because I only noticed a very small degradation (judging by reported charge %) in a flagship device after 3 years. A midrange phone from 2020 with heavy usage (charged twice a day sometimes, often using a fast charger) for 2-3 years did not have noticeable battery degradation. A low-end device from 2016 had no noticeable degradation after 4-5 years. Another 5+ years old second-hand phone had some, but nothing catastrophic. The only case of bad battery degradation (shutdown at 20%, unreliable gauge, etc) I have only seen in 10+ year old devices.

This, unfortunately, has been a thing for over a decade. I was excited to discover that Samsung Galaxy S3 (i9300) is/was one of the better-supported phones for custom ROMs… until I realized that the one I have is a Sprint / Virgin Mobile version (d2spr), which looks the same but uses a different SoC entirely.

You might end up needing postmortemOS

On a serious note, you can run without a battery

Time Management: The Game

Probably the most valuable IRL skill you can learn in a game. Or you can just chill and fish for a whole year, no one’s gonna judge you.