Woosh! (The sound of what you just said going right over my head...)
My original 2012 PIC based uploader charlieplexed the opto LEDs but there was never a PCB for it so it would have been a nightmare for anyone to try to replicate that original design on veroboard. Having a PCB available changes everything though, all the builder has to do then is put the right parts in the right places.
Nice PCB - will be interested to see how this progresses.