SmartCrawl Analysis modules slow down back-end

If the "Page Analysis" and "Readability Analysis" modules are active on "SmartCrawl -> Settings -> General Settings" page, saving content in back-end slows down terribly.
This affects especially menu saving on "Appearance -> Menu" page but saving posts/pages is slower as well. Sometimes it's just slow, sometimes it's causing timeout errors.

Switching both these modules off instantly fixes the issue.