To be honest I am very disappointed with ThinOS 9.1.3 as well. My 3040-clients running it as a test are crashing or shutting down by themselves for no reason. The Citrix client freezes sometimes during smart card authentication. We tried if skipping Citrix in favour of RDS would make things better, but since there is no support for smart card redirection in the WVD/RDS client in ThinOS 9 we quickly abandoned that plan as well. Migration to ThinOS 9 is still on halt waiting for newer and hopefully more stable releases from Dell. We are still on 8.6 in our production environment.