Unfortunately, this doesn't seem to do anything. I ended up opening all of my 216 bookmarks simultaneously and that way, all available favicons were loaded. For bookmark ordering, I had to use a different product too, but I like the notion of one extension that satisfies both requirements and will try checkmarks again from time to time, then reevaluate my star rating if checkmarks should suddenly become functional.

O/S is Mint 18.3, running natively as sole O/S on a MacBook Pro 13.3" pre-retina.