[butterbox]

Butter Box (https://likebutter.app/box/) and Internet In a Box are two modern descendants of the concept. Both run on RPis (and, nominally, some other hardware).

Putting together the images isn't terribly difficult. For Butter Box, we just run a script to install all the things we want, then make an .iso of that, which we distribute on our site and in hardware form.

Those onboard network cards are indeed a problem. You can get single-digit # of simultaneous users. But other than that, they tend to be very fast for large files since you're not going out over the Internet and can saturate the WiFi connection.