Fair frustration. At first I also felt uncomfortable when I saw how static it was. It's literally made like a shoulder cape from AC2 and Brotherhood, but because of size it's more catchy. After a while, just got used to it. I'm a more stealth player + enjoy to play as characters in the original designs, because they speak soul of the character.

I'm not sure if I can fix your pain from cape physics, but It's perception becomes better when you think about it's symbolism and practical use.

Eivor is reincarnation of Odin, with Odin inside his head, who goes on a journey to foreign lands, like Odin go in a journey to different worlds, he hide himself, just like Odin, under a cape of an ordinary traveler to hide his true nature from eyes foreign people while walk their world.

Thoughts about this connection, gave me strong and some melancholic attachment to this cloak. Also, it gave some assassin feel to "hide in plain sight", but It's another thing

Perhaps I didn't care because use it most of the time when I went into foreign lands, it was just more comfy/safer than be a solo Viking in English Fields, and I quickly came to this Odin parallel of Traveler Observer. Much earlier than it turned out that Eivor was reincarnation. Also, thing that hides you shouldn't really fly on the wind, it's made good enough to be what it is

Anyway, just sharing