IMO their approaches to the constitution-of-rights and the structural constitution have diverged dramatically for quite a while.

One could provide sensible justifications for that (different enactment contexts; abstract liberal principles have less to say about latter)! But iirc they pointedly avoid drawing a sharp distinction, which goes to your point about theories of interpretation.

And the distinction-in-practice leads to tension, eg when collective sovereignty gets a lot more weight in one context than the other