Hi. Welcome here. You have come to a very good place for understanding this better. Your BF is very much on the fetish side of things when it comes to CDing. Not all are. I personally do not dress for sexual reasons, although it is as common if not more common for CDers to have sexual outlets with their CDing.
From what I understand for those who are highly fetish with their CDing, that it will not lead anymore toward transitioning than from those who are not fetish about it. Possibly even less likely. It may though progress toward him being more open about it in the future and possibly going out publicly dressed. Some do, some never do.
My best advice would be to sit down with him and have some discussions, some real heart to heart talks about how he really feels, not just from the sexual outlet part of it. Then, find some boundaries for yourself that allow you to get what you want and need from him in terms of not just sex, but of all physical intimacy. Hopefully do so in a way where he can still feel satisfied for himself as well. It may take a bit of time to figure it all out, but compromises can be made on both sides and lead to a good outcome for the both of you.
