Here is a thought.
To me, being a poseur is wanting to be someone else, when it is possible to be so. Examples are...if you want to be a Navy SEAL, then be one..it is possible!
One who chooses to emulate a fashion from history, or a manner from history is not a poseur, but a re creationist. A person who is of Scottish heritage, and celebrates that is merely enjoying and reconnecting with their culture, with the assumption that they are admitting that they are who they are. If you are dressing the part, and adopting the accent and syntax, and passing yourself off as being from somewhere you are not...then you are a poseur.
I was brought up in a Scottish home in America (Missouri). Until the birth of my kids, I was the only American in my family. I had to deal with stupid teachers that almost literally beat my accent out of me...shame that, but I've got my beautiful Doric voice back. My family is known in Aberdeen..most still live there, and in other parts of the UK...so I am known as "he who is in exile" LOL