What is packageWriteRedirectionCompatibilityShim?

The only reference to this that I can find anywhere on the internet is buried in https://docs.microsoft.com/en-us/windows/uwp/packaging/app-capability-declarations as a restricted capability.

It seems that this might be a possible future replacement for the PSF FileRedirectionFixup, at least for some applications.  Especially if it works the way I think it might.  As I have been considering writing a Copy-on-Write based replacement for that shim for the PSF, it would be helpful to share information with your partners to prevent wasted duplicate efforts..