Solidify the notion of pivots/tags

[mlorbetske]

How to they aggregate and what happens when a parameters query is executed over two templates that unify on ID but have different options across the pivot values defined in each?

Ex. Template A (My.Template) supports C# and has a parameter called X but not one called Y, Template B (My.Template) supports VB and has a parameter called Y but not one called X.

An aggregate template might be the answer here, with the individual templates with their parameterizations being contained as children of the aggregate and their common metadata being exposed in a unified way (name, description, icon, author, etc.)