That is why I always copy from my.uniden.com to an Excel file anytime I do anything to a scanner. All of my serial numbers, electronic serial numbers and keys for upgrades are saved in the file.
I have an SC230 registered in 2007 and a BCD996T registered in 2010 on my account now. Didn't even own a Uniden until 2020. Both my 436 and SDS100 are there, which are the only ones I registered.
While it certainly would be nice for Uniden to clean up the database, it really makes no difference as once you get and install a feature key, it's there forever and only Uniden can transfer any key if it's ever necessary to replace your motherboard.
The keys stay with the radio, not the owner so if you sell it.. the new owner "owns" the keys