Hi @NesTo and @stiebel,
Thank you for introducing and discussing this suggestion!
I personally also still see "out of bounds" as challenge for many teams and making it even harder may make it discouraging to many beginners. We would like to avoid that if possible.
At the same time, I would very much like to encourage teams to experiment with localization of any kind, even if that would mean ultrasonic-based sensors get used much more. But this would very probably mean different fields for Lightweight and Open as @stiebel mentioned, since the idea of Lightweight is to be a sort of an introductory league. Different fields would mean a ton of logistical issues which would in turn make the competition a bit more difficult to organize.
To some it up, I wholeheartedly agree with the objective but I am not sure making the lines thinner would be the best way to achieve it. That being said, we'll still give it a proper discussion within the TC committee and let you know the conclusion.