Sadly there are also 'secret prefs' that are considered so potent that they're not exposed by default in about:config

If you know about them, for example from reading the code, you can create them. So at present about:config is a strange sort of place with lots of knobs but not all of them.

is there a good list of those prefs? or perhaps I can scan source code for some string

Frankly, these secret prefs are basically either:

- prefs that a developer was too lazy to add to the list of pref; or - prefs that serve only during automated tests.

You could scan source code for `Services.prefs` and `nsIPreferenceService` if you really want to find them.

If there's something you really need to configure in Chromium and it's not available as a flag, you can add that feature and submit a pull request. It's an open source project.

Looks like you don't know about chrome://flags/

The thing is, flags in Chrome exist only until Google decides it shouldn't be an option anymore. Then they take the choice away from you. I disabled the material "design" styled themes for as long as I could, until the flag disappeared.

That's not really different for Firefox, there's just a different organization making that decision.

Chrome flags though die out so fast there's virtually no point in exposing them at all, it's disappointing and frustrating almost every release.

Firefox has been killing off features year after year I dont see why you trust them to be better in that regard.

It’s not remotely as complete as about:config

chrome://about/

That's just about:about, not an about:config replacement.