Each new DNN ID is generated based on when their policy valid Bitcoin transaction is created, and its order position in the block.
A policy valid Bitcoin transaction is one where it's a self-transfer and the transaction fee is set at a minimum of 5 vBytes.
For example, I did that for myself using my Bitcoin derived address from my nostr address (this is also an important point) and got the numbers n4.8 and b922664.8 (n as in nostr/DNN, b as in bitcoin).
The first number in each is the entry of where the transaction took place, and the second number is its position within them, in the context of policy validity (self transfer, minimum fee, order based on amount).
From that it's already unique and will always be so.
From there, the encoder transforms that number based ID to a human-readable and memorable one. That n4.8 turned into nABCeAbsurd.
n = DNN/nostr prefix
abc = batch of blocks of an upper limit if 15,600 policy valid transactions per block
e = block position within a batch
(future numbers) = cycle of 78,000 blocks
absurd = bip39 mapping to the policy valid transaction position within a block ordered by highest paying fee rate
So, with that number based ID and its encoder results, IDs will always be unique (and all are already created technically, just born yet. This is infinitely scalable, where I simulated results from 10k and a 100k years later and it still gave human-readable and memorable IDs). No collision.
So the IDs exist, and you get what you get in the end based on timing and fee rate. I'd imagine most people won't try to time to acquire a ID as other people would bump them up or down in position, they'll just do a self transfer and they get what they get. My name is still freakoverse, but my ID is nABCeAbsurd, and my I can have whatever website name, and however many, under that ID/TLD.
Regarding SEC, I'd love to (wanted to go there for a while), but most likely I'm unable to (though there would be someone there where he might do what he did last time, which is do a quick stream to everyone there of projects from people that aren't there).