The Kid-Size league has been a great invitation card for new groups to enter the RoboCup. Low budgeted teams uses this category to evidence their institutions in the field of robotics and helps to raise investments, enabling them to improve their robots for participating in the leagues with taller robots.
However, the Kid-Size league can also cause teams to become accommodated in this cheaper and, somewhat, easier league.
Thus, I believe it would be good to turn the Kid-Size league into a Drop-in league only, with restrictions of size and the requirement of listening to the game controller.
The main idea is to reduce the prestige of the Kid-Size league, making it more like an Entry Category, or even a Base Category, in which the teams could compete in order to foment the investments in their teams. Also, this may cause the teams to interact with each other and develop their robots.
As the teams grows they will migrate to higher categories.