Belatedly, here’s video of my session at WPCampus 2018 on the Pressbooks REST API: https://www.youtube.com/watch?v=Lq8y3wgJJs0
Many thanks to @brad for getting us onto the API train and for everyone who gave me feedback on my slides 
EDIT: Slides are here — https://noti.st/greatislander/fseZh4/an-api-for-open-educational-resources
Lots of great information, not sure if the echo in the YouTube video was a result of my computer malfunctioning.
However, I am re-inquiring into how much of the evolution of the PB API will affect the ability of PB to operate in a stand-alone environment (i.e., a PB server not connected to the Internet, acting as a mobile WiFI system)?
The echo was on the recording, unfortunately.
To re-answer your question from last fall, only uses of Pressbooks that involve communication with remote websites will be limited by working in an “offline” mode. The REST API allows a variety of additional features that involve communication between different Pressbooks networks. None of these features would work without a network connection anyway so you don’t lose out on them by running Pressbooks “offline”.
(As a sidenote, I sometimes use the Airplane Mode plugin when I’m working on Pressbooks in areas with spotty internet connections (e.g. on VIA Rail 
) and most core functionality behaves as expected.)
Thanks for the update.
Interesting plugin in the universe of WP plugins
I assume you are referring to MAMP, XAMPP, or LAMP/WAMP instances when “running Pressbooks “offline”" ?
I’m referring to any situation where Pressbooks is run on a local environment (e.g. not a remote server) and accessed from that same local environment. So yes, that would include something like MAMP, or Laravel Valet, or Vagrant, or anything else that fits the bill. I think you’d mentioned running Pressbooks on a Raspberry Pi and accessing it from the same host— that would be the same thing.
Thanks but I missed the part about which tool(s) you used in your example…just curious.
cheers,
steve