For now... Google is developing AOSP more and more behind closed doors, which is more troubling for other Android based OS's. So even if e/OS is not (much) effected by this 'sideloading' thing, other choices Google makes will destroy something at some point.
If Google is going to build this "sideload protection" in the core of Android, this is going to be very bad, even for e/OS.
Fuck Google.
I think Sony allows the bootloader to be unlocked, so i would go for the new Xperia 10 vii and just put a beefy case on it to be honest. Not only does it have the 3,5mm jack, but also SD card slot, no stupid punchhole/camera cutout, has a good battery, is a 'normal' size (6.1"). If i didn't went with the Fairphone 6, i'd go for that one.
Those rugged phones are falling short in many ways, and most of them are pricey too. And Motorola isn't what they used to be, sadly.