You've got a handle on it, roughly. The issue is exactly when/if someone takes a username. The tension is between links using the did, which wouldn't ever break

You've got a handle on it, roughly. The issue is exactly when/if someone takes a username. The tension is between links using the did, which wouldn't ever break, and the nice URLs that normal people expect to see. If that didn't exist, they could just always use the DID link and it would be fine. But regardless of what could be done, I'm just talking about what is the case right now. Which is that they break.