[Dovecot] Different Formats Per User?

For migration possibilities, we're considering whether it's possible to have Dovecot run some users using standard Maildir format, while other users would be using filesystem (LAYOUT=fs) format? We could determine which one's users have, but is there a way to tell Dovecot this information, and is it even part of the Dovecot design to deal with this scenario?

Thanks, Tony