We are tossing around the idea of having solution-defined snippets/templates. Would that meet the end goal, or would you still want to be able to define multiple templates within the same solution?
Solution defined snippets would be extremely useful too! As long as they get stored in a separate file inside the solution so they can be versioned while the solution file itself is ignored (generated locally).
That does indeed reduce the usefulness of multiple create file templates a bit, but they'd still be a good feature.
For solution-defined settings, we have a .va directory located in the directory that contains the sln file. The .va dir has user and shared sub-directories. The shared dir is intended to be in source control, while the user dir is intended to be .ignored. VA features that currently support solution-defined settings are hashtag filters, VA Step Filter and Source Links.