@Nizar BOUAZIZI and @vipullag-MSFT
From the testings that I have done so far, drive mapping is disabled if you access the WVD session from Web client.
Whereas, drive mapping is enabled if we access the WVD session from desktop client.
On a Windows 10 Multi-session desktop, drive mapping is enabled by default.
Hence, we have not made any changes.
Whereas, we have configured conditional policies. All Users will be able to launch the apps and desktops from Web client only. Even though they install desktop client on their desktops, they will not be able to access the WVD resources.
However, if the users are part of drivemapping exceptions group they will be able to access the WVD resources from desktop client.
By doing this we can have restricted users to access their local drives and printers from the WVD session, at the same time we also have users accessing their local drives and printers from their WVD session using desktop client connecting to the same session host.