How do electric propeller governors (or electrically controlled governors) work and what are their pros and cons? I am trying to understand why electric propeller governors are not (yet) prevalent given that they offer the ability to control the RPM with high accuracy. What is the typical architecture for an electric governor or electronically controlled governor? What are their pros and con?
As far as I know, there are two types of electric governors:

The governor has an electric actuator in the propeller hub like the Airmaster Governor. This removes a lever, but adds a number of switches in the cabin.

The governor is still hydraulic, but an electric actuator controls its position. (I think the PC-12 and TBM700 work like this?)


I am assuming that option 2 is not ideal as you need a separate actuator to control the governor cable.
I guess I do not understand how airplanes like a PC-12 or TBM700 (that only have a single lever in the cabin) regulate propeller RPM.
Thanks!
They are much more prevalent than you think, and have been in use for more than 70 years. Rotax 912 and 914 engines can be installed with electric governors from MT Propeller. Airmaster sells them as well. You may also be surprised to learn that nearly 90% of German operational Luftwaffe aircraft during WW2 used an electrically-actuated propeller system designed by Dr. Hans Ebert of the VDM (Vereinigte Deutsche Metallwerke, or United German Metalworks). One example of these excellent propeller systems is in the Smithsonian's National Air and Space Museum.
This article does a pretty good job of explaining how they work.