Naturally such changes are not intented to be done after one update, it's possible storyline in 4.87
And yes, Samura can greatly help Rheinland in food production. We mentioned Stuttgart (it seems if Synth retreat, Rheinlanders should in this or other way be forced to cultivate Paste there, in order to prevent massive hunger. Stopping terraforming, and returning to Stut's normal climate could take decades, if not hundreds of years) and Nuremberg, but we forgot about Baden-Baden. This planet is now capable of sea farming, in what Samura have experience from Junyo. Yes, time to 1st harvest can be hard, with food rationing, but Rheinland theoretically in max time 10 years is able to be self-sufficient in food production. Moreover, after full develop of Nuremberg, Baden-Baden and Stuttgart it could be even food exporter.
EDIT: Did I say sea farming? There's also Holstein.