I still use feathers on my arrows and when I took out my hunting arrows I saw the feathers had been flattened.
I thought of what to do then I got the idea to put on a pot of water to boil. When it was good and hot I took each arrow and held it over and in the steam for a few seconds and the arrows poped back in good shape, You just have to be careful not to leave them in the steam too long or too close to the source it Can weaken the glue.