Introducing the new migration experience from Google G Suite

Hi Everyone, I have tried to migrate 150 Mailboxes from G Suite to 365 by MS article https://docs.microsoft.com/en-us/exchange/mailbox-migration/perform-g-suite-migration I need to migrate by small batches of 5-10 mailboxes per batch (Endpoint configured by 200 initial syncs and 100 incrementals) In some step, after 3 or 4 batches that running concurrently (each department batch includes 3-6 -> 5-20 GB per mailbox) I have reached "limits" of MaxConcurrency value 5 and each next migration batch fail with same error: Error: MigrationProvisioningPermanentException: This operation exceeds the throttling budget for policy part ‎'MaxConcurrency‎', policy value ‎'5‎', Budget type: ‎'PowerShell‎'. Suggested backoff time 2147483647 ms. --> This operation exceeds the throttling budget for policy part ‎'MaxConcurrency‎', policy value ‎'5‎', Budget type: ‎'PowerShell‎'. Suggested backoff time 2147483647 ms. I have open a case via 365 Support - [Ticket #:16174789] After 3-4 days (logs, reset PowerShell connections) and "escalation" to the next support level , I get the answer : - We can't do anything. For tenant with 150 mailboxes the maximum that Microsoft can to assign in MaxConcurrency value (5) Anyone get same error ? Anyone have some ideas ? Thanks in advance.