I think a viewer would be nice ultimately. But we haven't exactly figured out how the solution might look like. ideally something that allows you to create datasheet-like snapshots of part of your design?
Side-by-side schematic symbol view / code view that are actively synced to one-another in real-time. Schematic view allows basic arranging of parts, editing interconnects, triggering jump-to-reference within the code view, adding probe points for SPICE, displaying SPICE output graphs. Code side does all the heavy lifting like creating new parts, scripted behaviors, editing component values, all the cool shit that would be a nightmare to sort into a GUI.
Much easier said than done, of course.
For the spice graphs, having a jupyter notebook-like interface would be great to document why your design looks the way it does.
If you have specific ideas or drawings of how this might look like, please send them over in our discord server :)