Have you ever considered taking things out of the limited breadboard mode, so that you can have an unlimited board to play with?
That is, an unlimited size (memory allowing) board with custom connectors underneath.
Which leads to the second idea...
Have you ever heard of the Kansas collaboration environment that the Self programming language used (it is the forerunner of all modern GUI-based collaboration systems, just as Smalltalk is the forerunner of all modern GUIs).
Have you considered having a group simulator option where people can wire their own individual breadboards together in a collaborative environment?
This paper describes the Kansas development environment, and this video segment shows it off in a very limited way (the part about "radar view):
https://web.media.mit.edu/~lieber/Lieberary/Softviz/CACM-Debugging/Kansas/Kansas.html
Look at teh video at 14:10, about the "radar view":
An option for gapless power rails would make layout easier. I know breadboards have traditional gaps between each run of 5 holes, but breadboard PCBs usually have gapless rails.