"Which address" is up to date with the DVLA? Your drivers license? We don't care about that and neither do the parking firms. What about the V5C? One of the most common mistakes is when drivers change address, they update their drivers licence but forget that the V5C is a completely different requirement.
Anyway, dumb move identifying as the driver. Never mind. You can safely ignore every thing from now on. Debt collectors are powerless to do anything except to try and intimidate the low-hanging fruit on the gullible tree to pay up out of ignorance and fear.
APCOA have never taken anyone to court over a PCN and I seriously doubt you would be the first. Ignore them and eventually they will give up.
...I didn’t realize their drop off was camera based not barrier like any other airport.
Not sure how many other airports you've been to recently but most are now barrier-less and ANPR controlled.