AFAIK because of the distance, colonial governors had some autonomy. I think it would be interesting too if it became a new king demand - for example, making you choose between a tax raise or the king imposing a certain civic upon you. That's a pretty interesting idea. You could use the BellsStored as a cost for such research as well as normal YIELD_IDEAS, which would expand the use of bells. In case you choose to do so, I recommend changing doBells() in CvPlayer so that the king increasing units in the REF doesn't deplete the BellsStored, but rather depletes a second variable that is also dependent on bell rate. You could just set a loop and then the AI will research the first tech that fulfills the requirements you set in canDoCivics() in CvPlayer for techs. AFAIK the AI would eventually start setting people as inventors even without any special modifications. I could help with the coding.