The CUDA backend cannot be used in the packaged WindowsAppSDK application

[KFeiHe]

The CUDA backend cannot be used in the packaged WindowsAppSDK application, but works normally in the unpackaged WindowsAppSDK application.

[DarthAffe]

First of all: I've no experience with WindowsAppSDK applications so I can only guess what's going on there.
What exactly does "cannot be used" mean? Is there any error message?
I'd assume it can't find/load CUDA due to some security restrictions in packed apps, but I've no idea how that could be verified.