[css]

The plist is probably a binary plist (header bytes `bplist00`) generated by NSKeyedArchiver, and then the specific data you need is encoded inside. Edited iMessages are stored in the exact same way. Luckily the plist itself is not that complex–but typedstream is pesky to work with.

[wpm]

The plist is no issue, but it's the values therein where you run into typedstreams. For every setting for the Script Editor's formatting, is a separate dictionary, with an NSColor and NSFont key set to a data type value. The data is a base64 encoded `streamtyped` file. Passing it through base64 decode and running `file` on the output gives back `NeXT/Apple typedstream data, little endian, version 4, system 1000`, just as in the OP.

[wpm]

The only reason I want to do this is because I wipe a Mac nearly weekly, and need it setup more or less the same way again. I could probably just drop the .plist in that directory and bobs your uncle, but I also would change the fonts Script Editor is using to a third-party font not installed, so I don't want to have to worry about weird order of operation BS, and also find a way to set it to any arbitrary font, as I often change out the "fixed width" font I use in all the editors for that week (I have favorites, not just a favorite, gotta keep it fresh, ya know).

I figured that since Script Editor, and the AppleScript components of macOS are so old and creaky, forgotten leftovers in the Yellow Box that no one bothered to fix. I had no idea typedstreams were still being used in modern Apple software.