Firstly, I seem to be the only one in my guild to have started and completed the quest Involving Redguard messenger (in Daggerfall) and the 2 main NPCs. None of my guildmates could find the Redguard messenger in any faction city. No one could find a sealed letter via Crown Store either.
Secondly, the final fight in the dragon lair is glitchy. Got him to 0.5% HP and he stayed there for a long time refusing to die. Had to restart the fight with a purposed fall death, resurrect, then cross over the drawbridge again to fight the boss. This time, battle went smoothly, mechanics seem to be working (I think) and ended with his death.
And lastly but not least, thank you for the Dragonguard/Akaviri vibe in this quest, short it may be but the lore did shine through a bit. The revisited mechanics (from Murkmire) is fun too.