I have a package that contains a GCV object.
The GCV object contains a structured GCV that has changed:

I have added some new fields to it and I've built a new package version.

Now I want to update a driver that contains the old package.

I get this error:

Defintion 'myNewField' missing in one of the instances in a structured GCV.

And I can't continue...

Of course it is missing since it is new

The question is how can make the package upgrade process add the new
field(s) to existing instances? Can I do it via some kind package
upgrade stylesheet?