Sync project migration fails with missing Exchange Online Connector (4383937)

Upgraded from version 9.2.2 to version 10.
The DPR_Migrate_Shell process fails for the exchange online sync project.
The error shown is as follows:

[2526008] Error applying 5 patches to object (Exchange Online organization 'msg services ag' (65f55718-6b60-4436-8482-c080b10ae689)).
[2526011] Error applying patch (ADO#458274).
[1777296] Error updating schema of system connection (Exchange Online (msggrouptest.onmicrosoft.com))!
[1777292] Error connecting system (Exchange Online Connector)!
[System.Exception] [System.Management.Automation.RuntimeException] ExchangeOnlineManagement powershell module is not installed
[System.Management.Automation.RuntimeException] ExchangeOnlineManagement powershell module is not installed

We installed Powershell 7, the concrete needed version as of stated in the installation requirements 3.6.0 and other newer versions as well.
Confirmed with 'get-Module -ListAvailable'.

Identity Manager 10.0 requires the Exchange Online connector host to have PowerShell 7.x installed, plus the Exchange Online PowerShell V3 module, and the documented supported ExchangeOnlineManagement version is 3.6.0. The same requirements list also says the Microsoft Graph PowerShell module is required on the synchronization server. 

There are various issues when installing these 3rd party components.

Multiple problems on installing the ps 7 and the modules in combination of the isolation of powershell processes in IDM.

1. PSModulePath was not extended with additional paths

C:\Program Files\PowerShell\Modules 
C:\Program Files\Powershell\7\Modules

2. Install-Module installs, even as admin-console in the user folder instead of the global installation folder. The parameter -Scope AllUsers is now obligatory to install

2.1 I installed once without this parameter, all following install-module or update-module does not update these paths. Only uninstall-module followed by a new install-module -Scope AllUsers helps. 

3. Restart the server, as per need.

After all this, the synchronization project could find the module and the migration worked.