Did anybody tried and maybe automated migration from Modoboa to Stalwart?

[phpony]

I'm looking into the possibility to run a one-day migration from existing Modoboa with 20+ domains and 500+ boxes with ~200Gb mail to Stalwart, so I'll need to move the domains, accounts and existing mail. Modoboa is set up with MySQL and stores mail in Maildir (vmail). I'm OK to manually create domains and setup new DKIM's for them, but accounts, aliases and contents migration must be automated in order to achieve everything in one day.

Few months ago I've run this scenario once as test run:

1. New clean setup of Stalwart with MySQL backend.
2. Create all the domains manually.
3. Export users data from Modoboa as SQL, transform and import into Stalwart's tables
4. Rsync maildir to this server and run import from Maildir for each user.

It took few days and at first glance it worked. I had to restart Stalwart few times, tinker with it's caches and slam few buttons in web admin for I was able to finally see all accounts there and log into few of them and check mailboxes. Yet I'm still not sure that simple feeding the users data to MySQL table was enough for Stalwart to properly work for all users and deliver incoming mail into boxes. Also I'm not super found of use MySQL as backed for Stalwart, I'd prefer to migrate into internal data storage to properly manage users with Stalwart's web admin later.

So, now I'm looking into another possible scenario:

1. New clean setup of Stalwart with integrated storage.
2. Create all domains, users, aliases with REST API from Modoboa's data (maybe create an universal shell script?)
3. Rsync maildir to this server and run import from Maildir for each user.

Did anyone successfully migrated from Modoboa to Stalwart? Did you used REST API, or is there any other easier way? Any advises, notes, hints, workbooks on this?

P.S. I'm not asking for a compete solution - I'll manage the migration myself, just curious about other peoples experience before I step on the rake myself :)