So with the new client integration plugin that basically acts as a web socket service, I updated the AppStack to include the new versions of the Client Integration Plug-in. Unfortunately, it appears that that is not possible.
After capturing and ensuring vmware-csd process was not running, I went ahead and finished provisioning the AppStack. However, when I logged in to the desktop, attaching the appstack that I just provisioned, I found out that the client integration plugin wasn't starting up when I browse to the Web Client. Looking at the web console, I noticed that a web socket request was failing due to unresolvable host name vmware-localhost. I found out that Client Integration Plugin adds a vmware-localhost entry to the hosts file in C:\Windows\System32\drivers\etc directory, but it required me to flush the DNS before the hosts file took effect.
Even then, I found that the plugin would not work, so delving into the CIP log files showed that the certificate was missing on C:\ProgramData\VMware\CIP\csd\ssl directory. And I found that the certificate generated during the install was not captured to the AppStack.
I reviewed the snapvol.cfg within the AppStack and, sadly, I found that it was set to exclude anything under ProgramData\VMware directory. (EDIT: As I found out, the writable UIA also includes this exclusion, so even Writable Volumes UIA will not work correctly with VMware CIP)
Any other thoughts on how to make the new version of client integration plugin work with AppStack? The only thing I could think of is having allvolattached.bat script on the AppStack running vmware-csd.exe --install and ipconfig /flushdns, but generating keys and certs takes a loooooooooooong time. (It's a single threaded openssl process, so SMP does not help)