This is the german colonial empire that we all know. Most people here agree that it is impossible to prevent the decolonization of africa based on three principles:
1- If you develop your colony, they are going to ask for autonomy since they can sustain themselves and does not want to be extorted by the metropolis;
2- If you do not develop them, they become a economic drain unable to be kept;
3- Depending of how the 20th century progresses, the hold in africa will become harder as some form of cold war will make your enemies support the independence moviments, that might force a colonial war that ends being a economic drain and make you leave the colony. Even if all europeans agree to keep their colonies and there is no foreign support for rebels, the point 1 and 2 still remains.
based on that I came with a idea: Could the german empire create in africa something close to what the Uk did with the dominion system? On this scenario they do not lose their colonies for some unspecified PoD, and as time progresses the main german companies like Krupp, Daimler, Siemens, etc, creates their own colonial branches, and by the 60s or 70s the colonies are granted "independence" with the Kaiser remaneing their head of state and with some form of governor general appointed by Berlin. What do you think?