Dovecot fails with the way user/pass are stored by hestia

As I was implementing a fast search for email (trying both lucene and solr, lucene is actually faster, still) through IMAP, I bump into the problem that dovecot can’t parse or index by users properly;

root@myserver# doveadm -v index -u '*' '*'
Error: auth-master: userdb list: User listing returned failure

doveadm: Error: Failed to iterate through some users

This seems related; email - Dovecot user lookup fails when using username@domain format - Server Fault
but as I already have hestia running in production now, I can’t just change the way the users are stored in db. I was wondering if anyone has a solution for this?

The dovecot also logs this;
auth-worker(16853): Error: passwd-file: User iteration isn't currently supported with %variable paths
when I try to run;

# doveadm force-resync -A '*'
Error: auth-master: userdb list: User listing returned failure
doveadm: Error: Failed to iterate through some users

which made me find this: dovecot - How do I configure doveadm -A with passdb? - Server Fault