[bulatb]

The propagation "speed" is the effect of clients honoring the records' TTLs. Clients and intermediate servers are responsible for pulling updates to whatever records they believe are stale; the DNS itself just sits there serving queries.

Clients and caches sometimes disregard the TTL or use their own, so sometimes changes to a record "haven't propagated" to some clients, but what's really going on is something that's supposed to keep its info fresh decided not to.

Though it's possible for clients to get out of date, the story of a built-in propagation speed you can't do anything about is based on misconceptions. The record owner has a lot of say in how and when their records get refreshed.