As for a "solitaire game". I think the best thing I can do at this stage to support solitaire play is make the game better overall. Update 3 includes so much more material to help support play: encounter cards which allow you to instantly make NPCs by combining a disposition and intent card; more handouts; significantly streamlined, clarified and consistent rules in too many areas to count; a new game mode in the core (now called Crewed) rules that focuses on trade; more detailed rules to allow you to repair abandoned structures as you explore them; and so on.
I keep putting solitaire off - but my hope is that solitaire naturally flows out of the way the game is designed; for those people who choose to play that way; rather than trying to support two separate rules systems.