Hi, I realized this has been brought up before but has been strike down due to the reason that it would be seen as rude, RP-wise.

However, I would like to suggest that if you're mounted, while interacting with at least the vendors or NPC that make conversation in the passing (Like the one that just tell you short background info rather than you having an actual conversation/cut-scene with them) you should be able to stay mounted so that you don't have to wait a few seconds to re-mount after you're done.

This can be seen as not rude since the NPC that tell you short information would represent the people who tell things as you travel near them, not you who actually asked them something first.

For NPCs that required you to have deep conversation with (cutscene) or you initiating the conversation first, you'd have to dismount regardless.

For vendors, it might be seen as you are being in a hurry and the item bags are actually tied with the saddle instead of rather than being on your person (so you asked the vendor to put items in the bag instead)