This is from 2023, but this might still be a good read on how to get to a very low watt idle build, there’s a few more post on other older builds on that blog as well: https://mattgadient.com/7-watts-idle-on-intel-12th-13th-gen-the-foundation-for-building-a-low-power-server-nas/
S10e is great. It’s what I’ve been using as well, but it doesn’t get security updates anymore. Been using a custom rom which does get Android security updates, but there was a pretty serious SoC level security vulnerability which won’t get fixed for the S10e.
I’ll get a Pixel 8a instead. No headphone jack, slightly larger, only 1 physical sim. But can run GrapheneOS and have a long promised update period.