Hi
(1) handle canonicals and/or
(2) Handle structured data, and/or
(3) Generate sitemaps?
but still use 4SEF for the other functions?
4SEF has none of these features. 4SEF only does one single thing: create and manage SEF URLs.
And a second question is, can they manually edit o set rules for the sitemaps in case something which should not be indexed is being picked up?
You may be thinking of 4SEO, which has all the features you mentioned, and more, but does not do SEF URLs at all (that's what 4SEF is for).
If talking about 4SEO:
- yes each part can be individually enabled/disabled - although most people just replace JSitemap Pro, OSMap Pro, Tassos Google Structured data, RegularLabs ReReplacer, for half the price and with additional features not found in any of these (redirects, Search Console connector,...)
- sitemap inclusion: 4SEO really is an SEO extension, so it does, automatically, pay a lot of attention to only including in the sitemap what should be there.
For instance, as part of the background automated crawling process, it identifies duplicates and only include one of the duplicate cluster page in the sitemap.
And it of course applies meta noindex meta tag and robots.txt exclusions.
Lastly, you can specificaly exclude pages with simple settings (exclude /some-category/{*}) or sophisticated rules (per component, per URL). You also have a separate set of exclusion rules for images within pages.
Best regards
Yannick Gaultier
weeblr.com / @weeblr