Thanks to @LeifOlsson for doing the work in code to update Castra Prime to 2.1 (see Github if you're curious).
I have done some basic testing of this version on a fresh save - went to Castra, started up basic stuff, had some disagreements with the natives. I haven't seen any issues so I wanted to get this out there for others to test/enjoy. Please let me know of any errors specifically associated with 2.1, especially critical ones, which I will work to resolve ASAP.
(Sorry I kinda let this go for a while)