Well, but it's not an in-universe map. It's a source of truth for travel times. It makes. Aplenty big difference if it is 2000 or 3000 miles from Neverwinter to Baldur's Gate
My point was more about folks who were being stickers for exact story canon...
You responded to my post directly, but you seem to be addressing sticklers for setting canon, not me specifically. Given that, I'll try to frame my response in terms of setting canon (despite not being much of a stickler for setting canon, myself).
Here's my current best effort:
The
DM's Sourcebook of the Realms in the first edition Forgotten Realms box set includes a section which "explains the mechanics for calculating the distances between specific locations using Realms maps." The section explicitly refers not just to maps in the box set, but also maps "in related sourcebooks and other products." The
Running the Realms booklet in the second edition Forgotten Realms box set includes a similar section with similar language. In both cases, the mechanics require the use of a specific hex grid overlay. Maps without hex grid overlays "may be used for general discussion and explanation," but they aren't used by themselves to calculate travel times or distances.
If we accept the 1e and 2e rules for calculating distances on Realms maps as canon, there's no way to calculate official travel times and distances using the poster map from the 3e
Forgotten Realms Campaign Setting. The poster map has no hex grid so, per established canon, it is "for general discussion and explanation." It shouldn't be used to calculate travel times and distances without a hex grid overlay. However, no canonical overlay is compatible with the poster map's scale, and there is no official rule for rescaling overlays. To take distance measurements from the poster map, we have to perform one or more steps not included in the canonical rules for calculating distances on maps.
TL;DR: The Forgotten Realms box sets establish convoluted rules for calculating distances on maps. Those rules don't provide any official way to measure distances on the 3e poster map. Ergo, distances on the 3e map aren't canon.
If any stickler for setting canon is reading this post, how did I do?