I'm a bit confused on listing "Soft Power Button" on the 400 as "None". Does the F10 button not count as a "soft" power button? Was the word "dedicated" meant to be in there? I wouldn't call F10 a "hard" power button, since it doubles as a function key after all. I haven't opened mine to check out the tech, there's not a whole lot of reason to. Most users, I think already bought a RPi 4, or now a 5, if they wanted access beyond/behind the GPIO.
And I'm glad the Pi500 doesn't have NVMe. It's aimed at the education field. Include an SSD, and they'd be competing with Chromebooks. Although I much prefer seeing RPi in education in place of Google products, commercial/business competition would put it in a different marketing space and it probably would get ugly. If you want NVMe drive, buy an old refurbished laptop, or stick a keyboard on your iPad/iPhone, or hack the Pi. That's what we're supposed to do with RPi's, right?