The unique thing about an IBM PC compatible like this is that it has an absolutely massive library of software that will continue to work and be "supported".
You've touched on one of my favorite things about using this. There's so much software easily available for it that I could never even try it all even in 10 lifetimes. And it's easy to store too. For example, lets say the average program is 1MB. Then a tiny 128GB SD card could store somewhat more than 100,000 programs. Still not enough? This thing supports at least up to 512GB SD cards, which could hold something close to 500,000 1MB programs. I haven't tried 1TB yet. You can also store dozens of spare SD cards in the CPU compartment, so you can easily have more storage space and more software than you could ever use.
i.e. The first picture you see of the machine is running Microsoft Flight Simulator. The First. They knew this was the standard for compatibility.
My question would be Jet by Sublogic, and ... most unfortunately Xenix x86.
Which leads me to believe that... you need a very low power cMos CPU, to have that battery life.
There are 12Mhz Harris cMos 286s but they are collector items, and the next step is 486slcs, which may run Xenix 386 w/ TCP/IP stack, rather well.
It’s an ESP32. You can emulate any system you want.
Part of the point though is that emulating an original PC takes very little power. A 286 doesn’t get you much (who on earth wants to run a 286 OS)?
I could see a case for a 386/486 for running old DOS apps just so you have extra memory, but you could also simply port DOSBox-X to the ESP32 and do things that way.