we have text but its not great for drawing lines or connections on panels.

some examples of real-world industrial panels that have great depictions of the line style im talking about
http://static.messynessychic.com/wp-content/uploads/2016/09/controlpanel21.jpg
https://i.pinimg.com/originals/88/69/cb/8869cbe87401cbcb7af38a1928d0ce7f.jpg

I feel being able to draw lines on the panels will allow for more information-dense and immersive panels.
this could be implemented as basically a 'dumb' indicator that only has a color and no inputs and is free or fractional dye