Yes, you MUST have visited Throat of the World in order to trigger the repair quest. You will see why when you do the quest.
I know this, I've glanced at the requirements of a walkthrough. I have all-access there, and I've done the first Phial quest. Should be no reason why I'm not getting the letter.
Not sure. Did you actually go and do other stuff or just use wait time?
Ah, yes, I've tried both. Since doing both White Phial, the quest, and some time after that Throat of the World, the quest, I have normally kept on playing. But now I'm running out things to do with my selfish mage character, so I thought of this quest. Now that I have not that much to do anymore, I've tried waiting three days in a row (24 hours x 3). Still nothing. Too bad the rest can't be interrupted in this game - I'd like the courier to do so.

I'm curious to see what happens since I haven't been spoiled about the quest yet, I just know the requirements after which it
should've triggered.
I even tried console and added the letter to my inventory and read it. It cleared that only reading that letter doesn't start the quest. Then I tried some commands with the quest's early stage, like "setstage" and "setobjectivecompleted", and nothing. Visited the assistant at the shop, but he still didn't have any dialogue options. Just a random line. There are some commands I still could try, but I don't think they'll do me any good. I wouldn't like to use "saq" that starts
all the quests of the game.

If only there was a "sq"...
It can take forever, but it will eventually show up.
it's part of the bug, that it will never get trigger.
Plus now I don't know which one to believe.
