i recently saw that you now can use another piece of software named "migration manager" to migrate fileshares to the cloud.
For testing purposes i wanted to install it on my local pc where i have no admin rights (of course). It does need admin rights to install (for whatever cause) and the "SharePoint tenant admin" to proceed.
Ok as i am an admin i knew my client admin password.
But on the second page it takes this user, with no chance to change it, as the user who accesses the file shares?!?
I hope that the admin on your client cannot access these shares whatsoever. As it is a general user and should not be used doing anything else than its purpose.
So either allow the program to be installed in an user context (with the possibility to be a site coll admin for a specific site) and/or have the ability to change the user that is accessing these shares.
I know it's preview but this is not the right way where it is heading