It can probably be done and someone will probably do it. You'll need the parts, wiring harnesses/diagrams, control modules, a vagcom, and of course money.
I'd think DCC would be easier compared to the pp diff as you'd most likely be messing with engine ecu's an such.
Shouldn't need convincing, as pricey as some options can be, nearly all of them cannot be retrofitted at the same or less cost than the factory choice.
Understood. I would mainly want the LSD alone as I have seperate brake and suspension plans. The upgrades would surely be more expensive which is okay to tax those of us who were impatient and did not wait.
If you are after a diff after purchase you could easily go for a proper mechanical limited slip diff which wold still be a vast improvement on the standard non PP car.