Synchronize data from Jomsocial to Membership Pro

Hello!
I'm at it again trying to migrate an AEC setting to Membership Pro.

My environment at the moment:
Joomla 3.5.1
Membership Pro 2.6.2
Jomsocial 4.1.6
...yeah, I know, those are all outdated versions. But that is why the migration to Membership Pro is happening as AEC won't allow any updates.

I could migrate all the AEC profiles to Membership Pro, which actually worked quite well.

Now would like to synch the Jomsocial entries to Membership Pro and followed the tutorial 
membershipprodoc.joomservices.com/integr...hronize-profile-data

I activated the plugin and mapped the fields. That should be ok, but now the question is, how do I start the synchronization? The Jomsocial information does not seem to appear in Membership Pro.

I'm working on a test-site so I can give access to Admins here.

Thanks for any help!

P.s.: There are about 25k profiles  so could it be that its going to take a while until the info shows up? I need the Jomsocial data in Membership Pro for tax purposes;

The data won't show up and it seems I misunderstood the utility of the plugin, as, apparently, it only works for new accounts and synchronizes only the entries from Memebership Pro to Jomsocial and not the other way round.
We would need a custom plugin for the migration.
I can inform you about the tables and structure on the Jomsocial side if that helps in any way.

Tuan, let me know if you are willing to to code such a solution so we can progress in the migration.

Thanks!