I think the biggest issue with that type of re-enactor is that at times they may carry their SAS persona into the real world.
Some countries have real issues with fake SEALs and the like and when you do too good a job of impression people outside the game feel you've crossed a line. If sailors who have earned a Trident don't want outsiders wearing it then saying your team is doing it out of respect doesn't fly. You get lumped in with the other imposters since no matter how noble your intentions they are not evident in pictures.
If you still really feel the need to do these impressions then be ready for negative comments and if you post up a bunch of photos of yourself in action have an extra thick skin since that can draw unwanted attention in a very big way.
As an aside, most real units don't go into action bedizened with patches, ranks, jump wings and other qualification badges.
Airsoft, where nothing is hurt but feelings.