I'd love to find a post topper to add back some adjustability but the aero shape of the post means that's pretty much not going to exist off the shelf.
I have a guy who could make you one if you want one...
I'll PM you his details, I don't think it's his full time gig but may utilise workshop of full time gig so I don't know if he's keen on details being shared publicly...
I have a guy who could make you one if you want one...