Yes, you can trial CloudMigrator for free on 2 users for a maximum of 30 days.
All source platforms except File System and Mail Archives can be trialed.
A part of how our licensing works is, the licenses are tied to the destination domain name, so if you wish to migrate into two domain names, this will require two sets of licenses.
Users can work on the source platform without even noticing their accounts being migrated from.
We recommend not letting the users have access to their destination accounts, unless completely necessary, until the migration is completed.
In some Exchange environments, users may have login limits being exceeded (depending on the authentication method selected), in which case, the user will need to cease access to their account (or the migration should be run out of regular business hours by means of scheduling).
The average success rate of the 7 million users we've migrated so far is 99.9%
You provide a list of users for CloudMigrator to migrate, or you can use the "Get Users" function and tailor this list to your requirement. You can specify if the user migrates at all and if so (depending on the platform selected) Mail, Calendar, Tasks, Sites, Notes and Drive.