Support (lightweight) variants of pages
I really like the new feature that every page has a default local layer now. My global layer list is a lot more organized. But because this layer is local, you can't use its content any more to create variants of the page (e.g. with data changed, dialog boxes on top etc.). The next logical step would be to support variants of a page, each variant with one local sub layer. When specifying a target, you also could select the variant to jump to :)
While not a page variant, Interactions allow for directly jumping to or displaying/hiding individual layers on pages, e.g. to create logged in/out states or display elements on an active page.
Is this good enough for your use case?
You can achieve the same result with interactions now:
Instead of specifying "variants" of a page as target you can simply show or hide layers.