Hi,
I was confused and now I agree: both instances should be treated the same. To quicken the game, it would make sense to allow markers to continue to count whilst the thrower establishes the correct pivot location. That might also encourage players to focus more accurately on not travelling.
If a thrower disagrees, they might contest the call. That would stop the game.
Only other issue I see is that all defensive players are allowed to call “travel” and communication might be difficult. But from a active game play perspective, travel calls from other defenders are likely to occur on the throw itself or prior to positioning, when carrying the disc from out-of-bounds or something similar. In these cases, the stoppage would either be necessary anyway or the communication should be clearly visible.