TL;DR
Currently every item has a signal with some special signals for number, letter and color thrown in to avoid collisions. I want MORE.What ?
I want a practically unlimited number of signals. For that I suggest that users can define new signals in the way that blueprint are named. A custom signal should have a string (shown as e.g. tooltip when hovering over the symbol) and an icon made up of 2-4 of the currently existing core signals.With that one could for example create a signal: "Red Science Factory has Copper" <Red Science> <Copper Plate> and output the number of plates remaining in the buffer chest.
Why ?
In my megafactory with trains I want to prioritize and balance production. When the power plant is running low on coal then it needs to get all the coal even if the plastic production needs coal too. When both the steel smelter and green card require iron plates I want to split them 50:50. The brain of the factory has lots of those decisions it could make. But to do that it needs to know how many resources are at each production site.For the buffered output it is simple. The steel smelter emit a steel signal and all outputs are combined into a big network of green wire. Currently the lack of buffered ingrediences is put onto big network of red wire. That tells me when someone needs iron plates for example. But doesn't tell me who or what for.
I can use the signal "0" for steel smelter needs coal, "1" for steel smelter needs iron plates, "2" for belt assembler needs iron plates, "3" for electronic circuit assembler needs copper plates and so on. But a) who can remember what all those signals mean? and b) there aren't enough signals to keep them collision free on a single wire. So then you have to string up multiple wire networks in parallel across multiple outposts and you just hope you never accidentally connect them by accident. And how do you remember that the first red wire was for steel smelter needs and the second for electronic circuit needs and so on? That gets really confusing and error prone even with just 2 wires.
Some way to give signals descriptive names and to have more signals is wanted here.