Thanks for showing interest in MonoBrick Firmware and the MonoBrick communication library. If I came across as dismissive I am sorry. However a harmonization of the Microsoft API and MonoBrick would just mean extra work for me. Time that I would rater spend on the MonoBrick firmware – and what would the benefit be. I actually like the fact that you have different choices – some prefer MonoBrick communication library over Microsoft API and vice versa.
Concerning the Image I also fell that two different firmwares are ok. Our image is based on the LeJos image – without the LeJos teams awesome work there would be no MonoBrick firmware. However there are some differences between the two (and in the future more will be added) which would require some effort if they should be combined – and again what would the benefit be compared to the time you would have to put into a thing like that.
If you want to have a image that offer more that both Lejos and MonoBrick firmware you should definitely have a look at ev3dev. It should be possible to install Mono on the image and then use our DLL to control your robots.