Transmutation Stones!
I agree- I submitted this as an idea to bypass this issue.
Since all the endgame gear is going to be the same stat-wise, there should be a way to get several different styles on your current armor without losing that style. If I want 2 end-game level sets with different styles, I’d have to farm 2 sets of end game gear to apply those styles. I find that kind of limiting- once you have a style, you’re not going to want to change it as it was hard earned, and changing it would cause you to lose it forever.