Clean-up/double-check at crawler start only if page has changed, possible?

YaCy YaCy Peer-to-Peer
1

When creating an advanced crawler there’s a “clean-up before crawl start” and “double-check rules”.
Those 2 sections have an option to delete or reload if older than some time.

Is there an advanced option to do the clean-up and/or re-load according if the page has changed and not on an arbitrary date? Otherwise it seems a waste of bandwidth.

2

So you want to check if Site (or page) has changed, if Yes then recrawl. I like the Idea, but seems like it might be CPU intensive?