Increase concurrent migrations - Not working

Good afternoon,

In a migration from 2010 to 2013, the number of concurrent migrations is very low (no more than 4). Even adjusting the files "MsExchangeMailboxReplication.exe.config" (Session MRSConfiguration) on all servers that have the service "MSExchangeMailboxReplication" the concurrent migrations do not increase.

Any suggestions for a workaround?

Thank you,

Bruno