Installed the extension and added some pages, but it's clearly not indexing content of the pages because there are no hits for words that appear on those pages.
Given that the setting above it says "Make title and URL always searchable (recommended)", I think the setting for this option also should be something like:
> [ ] Make pages visited for at least n seconds full-text searchable
It's difficult to connect the grey text that says "Which websites do you want to make full-text searchable?" to the label of the option that controls full-text searching.