How to identify plist values for iterm preferences iTerm2 preferences are stored at ~/Library/Preferences/com.googlecode.iterm2.plist. (see also this post for details).
I can print its contents using
defaults read com.googlecode.iterm2.plist

Is there a way to I identify the plist value for a specific setting without setting the option in the GUI, saving it and checking the plist again?
I fail to find documentation on this.
I am specifically looking the following:

Save changes to folder when iTerm2 quits
emulate the button press of Save Current Settings to Folder
This is like asking if you can find all the words in a dictionary. Each author chooses the words they place when they publish, same as app developers code what they write into the code when they ship.
Before attempting to answer directly, in the past the user defaults were simple and wrote to one file. Over time, that design failed in several ways and a newer system exists across all Apple OS.

new https://developer.apple.com/documentation/foundation/userdefaults
old(er) https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/UserDefaults/AboutPreferenceDomains/AboutPreferenceDomains.html

In your case, the book is written and published and you would need a disassembler like Hopper to translate the machine instructions into code if that helps you list how it handles parsing and writing to the preference file.

https://www.hopperapp.com/

I’m not aware of a tool that disassembles only the preference handling, but that’s a super idea for side project if anyone is looking. Also, don’t overlook that the current preference system on macOS doesn’t necessarily persist any settings to a physical file. A developer can program that, but with iCloud and managed preferences, most apps skip that appendage as dead weight.  Again, unless dev document is generated when they ship the app, someone has to disassemble things to know implementation for each version of each app.