Is is possible to run the loading process for an unpacked extension in Chromium in verbose or debug mode?

Question

Is there a way to run Chromium's unpacked extension loading process in some kind of debugging or verbose mode, so I can get some specific insights into what is actually going wrong with the rules.json file I'm referencing in my manifest? All the obvious extension debugging tools depend on successful loading of the unpacked extension, and I apparently need some earlier debugging power.

Using Chromium version 133.0.6943.126 (Official Build) snap (64-bit) on Ubuntu.

I have a chrome extension with a bunch of declarative_net_request rules in a rules.json file. This extension and all its rules definitely work as expected in Chrome (or, at least, they did last time I used the extension a year ago).

Going into developer mode in Chromium and trying to load this unpacked extension only gives me this error:

Failed to load extension
File - /run/user/1000/doc/24af65bc/Plugin
Error - rules.json: Internal error while parsing rules.
Could not load manifest.

...Which is not terribly informative.

I can damage obvious things in rules.json, which causes slightly more specific errors to come up in the error message as I would expect. I'm less interested in getting an answer for what's going on with my specific rules than I am in getting information about a verbose error reporting mode for the unpacked extension loading process in Chromium.