+1. but would actually like them as additional ones to distinct between signals like arguments etc and display values

I don't think we need two sets of letters and numbers for signals, so long as the set we have is suitable for displays. For visual consistency I might suggest redesigned all ...

Most icons in the game, including the various line and arrow icons, have transparent backgrounds and dropshadows. These display well on the in-game display panels, and are readable from a distance. The current icons for numbers and letters were never great, and don't match the visual language of ...