I don't have extensive experience with all map templates. I can only provide specific details for the 6lm10a template. I agree with the idea of having two mandatory starting paths for both player and AI units. From the main junction (21, 22, 24, 25), for example, there should always be three paths leading to the 3k and 6k AI units, and one path leading to the corner (7, 8, 15, 16). As for the treasure area (9, 10, 13, 14), there should be easy access paths to the orange and purple AI units (22, 24), but never generate paths to the super-treasure area. It's also very important to never generate paths to the central zone (23) or within it. This is my specific proposal for this particular template!