Updates from Flexfolio (Bolt Version <=3.7.4) to the new version Flexfolio5 (on Bolt >=5) are in pipeline.  Some of the code base of Bolt CMS changed completely in latest development. Also some extensions (i.e. translation) are not needed anymore and translation is integrated. This makes Bolt CMS much better and easier again, but it is tricky to have some kind of 'automated' update.

Here you can find the docs for an update Bolt CMS 3.7 ---> 5.x:
https://docs.boltcms.io/5.0/upgrading/upgrading-from-30

All-mine.org is working on docs/guides how to update from former Flexfolio versions to the current Flexfolio5. In case you already started with an update and have a question please do not hesitate to write an email to mail@all-mine.org