Is the vendor lag intentional?

[Valinia-netherwind]

Well no, its not really as easy as that. The batching used in classic now, again is forced artificially. The game does not behave like it does in vanilla and pservers. Possibly due to the client each version uses.

@Kaivax

As with many other areas of WoW Classic, authenticity is our primary concern. It used to be the norm that combat flow and PvP balance were defined and tuned in a game where spell messages were resolved less frequently. There was a single game loop that processed all messages sent and received every server tick. Nowadays, the game processes multiple loops for messages of differing priorities. Spell casts are high priority, and have been for a long time.

For WoW Classic, we’re moving spell casts to a low-priority loop that will cause them to be processed at the frequency that best fits how the game actually played in version 1.12. Two mages will be able to Polymorph each other somewhat reliably, resulting in two sheep nervously pacing around at range. Two warriors will be able to Charge one another, and the end result will be both warriors standing stunned in each other’s original location.

It just emulates batching, and operates differently than it did in vanilla and it is noticeable, albeit being a nice approach to the original game.

So its not just done with “well both work with 400ms”. The way it behaves is still different. Id advise you to watch older videos (either original vanilla or Pservers like Nost) and see how they dealt with batching. There is a tangible difference on how batches work.