
Does NovaCustom just buy phones and installs iodeOS on them? Or are they involved in development of either?
This is the manufacturer, SHIFT: https://www.shift.eco/en/shiftphone-8/ Hardware does look easy to access, and should support custom OSes.
This is iodeOS: https://iode.tech/iodeos/, which looks like LineageOS + additional features and privacy-as-a-service kind of deal.

Stardew Valley has plenty of silly and funny moments to begin with. But the last patch added a “green rain” event, and during the first occurrence, all villagers are hiding inside, except Demetrius. This guy is just walking around in a full hazmat suit, collecting samples and babbling about mushrooms.

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.

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

PinePhone is $200. But the manufacturer offloaded all development onto the community.
Librem actually pays some developers, but their phones are $700+. And you will find many complaints about refunds.
Cheap prices are possible by economies of scale by manufacturers, but same manufacturers guard their proprietary hardware.
Also, how “pleb” are we talking about? Many people DGAF and just want their calls/text/apps to work.