Is it safe to mix dovecot import/backup/sync between dovecot versions 2.2.30.2 and 2.3.7.1?

I am migrating a server. The old one uses dovecot 2.2.30.2 and the new one 2.3.7.1. I don’t want to use any tool that might influence flags on messages. I am using Maildir format on both ends and I have a way to let one server access the data on the other (either using an rsync or a direct access).

Could I set up a sync between both to create a smooth migration?

Gerben Wierda Chess and the Art of Enterprise Architecture http://enterprisechess.com/ Mastering ArchiMate http://masteringarchimate.com/ Architecture for Real Enterprises https://www.infoworld.com/blog/architecture-for-real-enterprises/ at InfoWorld On Slippery Ice https://eapj.org/on-slippery-ice/ at EAPJ