What is right way to get mails from Gmail to Dovecot with doveadm-backup?

Dovecot doc is far from being perfect, thus I’m little bit confused what is right way to get mails from Gmail to local Dovecot.

See: https://wiki.dovecot.org/Migration/Gmail

After some struggle I have working sync of one user but is there something which can be tuned for Gmail and its unusual labels/virtual folders?

Do I understand it right that each gmail user must be synced separately, ie. via a loop as there’s no way to write multiple passwords users file (doveadm backup -F $ file).

IIUC the remote user must be configured in local Dovecot.

I currently have:

# egrep -v '^(#|[ \t]*$  )' /etc/dovecot/conf.d/99-migration.conf                                                                                                                                                                            imapc_host = imap.gmail.com imapc_features = rfc822.size imapc_features = $  imapc_features fetch-headers mail_prefetch_count = 20 imapc_port = 993 imapc_ssl = imaps imapc_ssl_verify = yes imapc_features = gmail-migration  # sed -n '/^namespace inbox/,/^}/p' /etc/dovecot/conf.d/10-mail.conf | \ egrep -v '^([ \t]*#|[ \t]*$  )' namespace inbox {       separator = /       inbox = yes } 

Doing sync:

# doveadm -v -o imapc_user=gmailuser@example.com -o \ imapc_password='gmailuser_password' backup -O '-$  GmailHaveLabels' \ -R -x '\Flagged' -x '\Important' -u gmailuser@example.com imapc: 

And after sync, I got this:

# ls -lF /mail/example.com/data/gmailuser/Maildir/ total 112 drwx------  5 localuser  localgroup    512 Jan 13 22:45 .[Gmail].All Mail/ drwx------  5 localuser  localgroup    512 Jan 13 22:46 .[Gmail].Drafts/ drwx------  5 localuser  localgroup    512 Jan 13 22:46 .[Gmail].Sent Mail/ drwx------  5 localuser  localgroup    512 Jan 13 22:46 .[Gmail].Spam/ drwx------  5 localuser  localgroup    512 Jan 13 22:46 .[Gmail].Trash/ drwx------  2 localuser  localgroup   3072 Jan 13 22:44 cur/ -rw-------  1 localuser  localgroup      6 Jan 13 22:30 dovecot-keywords -rw-------  1 localuser  localgroup   3684 Jan 13 22:43 dovecot-uidlist -rw-------  1 localuser  localgroup      8 Jan 13 22:43 dovecot-uidvalidity -r--r--r--  1 localuser  localgroup      0 Jan 13 22:30 dovecot-uidvalidity.5c3c0276 -rw-------  1 localuser  localgroup  21808 Jan 13 22:44 dovecot.index.cache -rw-------  1 localuser  localgroup   3148 Jan 13 22:44 dovecot.index.log -rw-------  1 localuser  localgroup    240 Jan 13 22:43 dovecot.mailbox.log -rw-------  1 localuser  localgroup      0 Jan 13 22:30 maildirfolder drwx------  2 localuser  localgroup    512 Jan 13 22:43 new/ -rw-------  1 localuser  localgroup    117 Jan 13 22:30 subscriptions drwx------  2 localuser  localgroup    512 Jan 13 22:43 tmp/