A very simple mod that tweaks the outfit of the "Visiting Advisor" used in the Dawnguard quests "A Jarl's Justice" and "Hide and Seek".
The quest targets in the quest "Hide and Seek", such as the Travelling Merchant and Travelling Bard, are at least attempting a disguise.
Unfortunately, the Visiting Advisor is very obviously dressed in the vampire outfit, which I have found to be very strange.
The journal entry even says "Isran has sent me to _ to warn _ of a vampire masquerading as a visiting advisor...".
That outfit isnt much of a masquerade is it?
This mod tweaks the outfit of the advisor to fine clothes. Which is what you would expect someone disguising themselves as one of high status to wear in Skyrim.
Compatibility
There is a SPID SkyPatcher version which has no esp, and an ESP version that simply changes the outfit record on the NPC.
Obviously the SkyPatcher version is compatible with NPC overhauls and such. It also wont need an ESP unlike the ESP version, so I suggest using that version if possible.
If you choose the ESP version you will likely need to do some conflict resolution in xEdit.
Credit:
Awuga for reminding me that this was a thing
Instructions
Requirements
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Skypatcher - https://www.nexusmods.com/skyrimspecialedition/mods/106659 (If you choose the Skypatcher version)
Visiting Advisor Outfit Tweak - No Skypatcher
1.0.0
Visiting Advisor Outfit Tweak - Skypatcher
1.0.0 - Requires Skypatcher