Discussion
Oh, my bad, not sub-addresses, sub-accounts. They still start with eight, but they are listed as different entities with their own balance, and you cannot spend from one while in another. You actually have to physically go to that account to spend Monero from it.
Interesting, didn't know that was a thing. Sounds akin to bicoin's wallet "accounts" which is just the last index in the derivation path, but results in a completely different xpub.