You had actually guessed right. The list of folders and paths used by the app are in:
~/Library/Application Support/Less app/lessDataFile.lessData
It's a binary plist (Property List) file, and from the look of the structure of the file, it's not meant to be messed with. It looks like an unintuitive serialization/dump of the internal state of the app.
It seems to store its preferences in this other binary plist file:
~/Library/Preferences/com.incident57.Less.plist
...but this file doesn't contain any of the folder paths used by the app. That's all in the lessDataFile.lessData file you'd already found.
It's standard practice for Mac OS X apps to store their preferences in a plist like that (that location, that naming scheme).
You can read and edit binary plist files with Xcode (and many other programming-oriented text editors for Mac OS X), or with the command-line tools PlistBuddy(8), or defaults(1). Or you can convert them to XML text files with plutil(1). Some tools for working with plists expect the file name to end in .plist, so keep that in mind if you're struggling to get a tool to open the .LessData file.
3Thanks for being clear about your affiliation and the neat answer. Welcome to Super User! :) – studiohack – 2012-01-05T05:32:15.480
1Great to see developers answering problems here! – Simon Sheehan – 2012-01-05T05:48:45.467
Thanks Bryan - that makes sense. I'd still like to be able to use Less.app between multiple computers, though. Is it possible for me to request a feature for "importing and exporting the configuration" then? – cwd – 2012-01-15T19:06:50.917