Currently in UI3, and when in Version History mode, the Design panel is not viewable.
While in Version History mode, I would expect to be able to view — not edit — almost all aspects of a file’s version including:
- Local variables
- Styles
- Style detail views (e.g. “Edit [current] style” modal but locked)
Anecdote: I somehow deleted an entire Variable collection and didn’t notice immediately, and when in Version History mode, I wasn’t able to see when exactly — or which file version — had the variables before their would-be deletion