Optimism DHT Network

[dennis-tra]

If I understand correctly, Optimism nodes participate in the Ethereum DiscV5 DHT. However, when I crawl the DiscV5 DHT with my crawler https://github.com/dennis-tra/nebula I cannot find any ENR that contains the opstack key which I would have expected because of this line.

Am I misunderstanding something? Is Optimism using a different DHT that happens to also use DiscV5? What would be the bootstrap nodes for that DHT?

Thanks everyone!