Multiple O365 Migration Endpoints

Hi All,

I'm planning a large scale migration to O365 which will see over 8k mailboxes migrated to the cloud via the Migration Wizard. The supporting documentation references a single endpoint entry but what I want to do is create multiple endpoints such that migration batches will be configured for each of the endpoints thus speeding up the migration process.

I plan to use multiple external A records such as MRS1.mydomain.com, MRS2.mydomain.com and so on.

Each of the A records will point to a single external public facing IP address which will terminate to a Citrix NLB which will then via content switching route each URL to a dedicated CAS server.

I want to understand what config will be required both in O365, On-prem Exchange so as to make this work.