I think the idea of having a multiplicity of stops of which, depending on the sample set, only some are enabled, as indicated by being lit dimly, is brilliant.
The brightness can be controlled by altering the duty cycle so no additional hardware or power supplies are needed.
Also, the Arduino can be "taught" which stops are to be enabled by pressing a piston at the outset which includes all the stops for that sample set.
I think this feature could be easily added to my decoder program.
It will be an interesting challenge to write the code and bench test it to see if the idea has merit.
John