I have just registered with GitHub and will now have to figure out how to pull.
I have found that CvPcb has problems if there are unused pins, there was a recent post here about the 6 pin 4n25
where pin 3 is unused. I find that KiCad works much better if ALL pins in a footprint are in the schematic symbol, even if marked invisible and NC.
I was not aware of the validation and will have to look for it. I tend to agree with Nicholas that this should run on Save. It would spot numbering reuse
A declaration at the start of the symbol library entry to know how many pins there are, would also solve another issue I have seen, where multi-unit parts don’t call appropriate footprints by number of pins if one of the units is not connected