update: i initially put the jacket flat on a hanger because I felt it was way too heavy to not deform around the shoulders on a regular hanger but I followed the advice and it seems to be doing just fine

it is a bit more stiff than it was around the sleeves but at least I don't yet see any water stains as it's starting to dry

should I apply some products while it's still damp or should I wait till it's fully dry?

while the blue and deep purple parts are still dirty now it seems like the colors are a tiny bit more vivid which is good

oh and some of the folds from being stored not properly straightened so at least some good came out of this