The main challenge (usuall) is to pass the "certification" step; which often involves insuring all the "package" images aren't too big; even though they're generated (color density).
(If you create a store package, you don't need "click once" ... don't even know what would be the point).
And you need to "access the internet" at least once; to distribut the app from the store (which support private distros). Unless you "side load" (publish) the package, which (usually) needs a device connection.
Packaging MSIX apps - MSIX | Microsoft Learn[
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