Purpose of new MSIX manifest schema additions?

Sunburst 

I, too, find the schemas frustrating and wish to add my thoughts.  Although I don't expect that Microsoft would respond to requests regarding the undocumented pieces, we can still vent about the state of the schemas.

I am so far avoiding any programing that requires me to generate or parse the manifest, because it is impossible to create a validator for the available schemas.  The practice of adding additional schema files each release, in combination with what I think of as different schema families (what you want for iot or mobile is a different subset of similar things), has led to elements and parameters defined without the logic about where these things belong.

Microsoft code itself must be littered with assumptions about what are legal combinations (or placements of elements in the XML) that outsiders can only guess at because quite too often it is not defined in the schema sets.  As an example, last year I looked into ApplicationAlias. It was a well defined element in itself, but at the time I was unable to find any element with documentation/schema that accepted it as a sub-element.  We are left to searching for examples where Microsoft actually is seen using it to understand a possible usage structure.

If Microsoft wants a robust partner environment I believe that they are going to have to clean this up at some point.