Change Code: %ToolKitHelper% %DefaultIndexNo% "ManualSetup" to Code: %ToolKitHelper% "%InstallMount%\%DefaultIndexNo%" "ManualSetup"
My advise - keep, at least, WindowsStoreClient (only back-end component of the Store) and DesktopAppInstaller (correct me if I missed something) This time you were lucky with NVCPL. The message from @shhnedo to you was absolutely correct (if you want have a deal with other DCH drivers or offline apps installations in the future). For example, Synaptics TouchPad driver (DCH) for some NB models or whatever else might need Store infrastructure working (at least, basic functionality).
@evildjkay He may be a high-end gpu user, which more often than not means that he'll benefit from newer drivers, and newer drivers are currently(and will only be) offered in DCH package.
I kept the two components you kindly advised me to retain and rebuilt my x64 image and reinstalled it on my spare SSD. This time Windows 10 21H1 x64 Enterprise installed NVCPL automatically. I then tried to use NVSlimmer v0.12 to install 496.49-desktop-win10-win11-64bit-international-dch-whql. When I pressed the "Install NvCpl" button I still received the message "You'll need a new app to open this ms-windows-store link". NVCleanInstall was able to install NVCPL without issue.
AVs will be triggered by lots of files these days, when you know the source and its intentions, consider it a false positive.