Hey sorry for not leaving feedback here before, I've meant to for a while now.
I think the biggest problem with exchange is the map flow. It feels convoluted, like everything is meant to be it's own separate place, but they were bunched together. I guess what I think needs to be done is some refining. I think the routes from one place to another need some cleaning up, so it's more organized. I also think that the point on the attackers left could be remade to be more interesting, which typically for me means that players have more options of how they approach and fight over the point. The point on attackers right isn't bad, but the middle area that's directly in front of attackers spawn seems to defeat the purpose of splitting the teams across A and B, and makes the point on attackers' right easier to cap for the attackers, as they have more routes in (I'd hazard that guess). I'm really not a fan of C. It's interesting to have a drop down to it, but I really hate how it plays out with red engies. I think the point itself could be shrunk down a lot. It feels like to me there's a ton of unused space at the top level (defenders spawn is massive, too). The lower area feels a bit too simple, and way too large. I'd love to see more options for approaching the point, which might mean remaking it altogether.
I guess what I'm trying to say is that I think the middle area in front of the attackers spawn makes the gameplay convoluted and difficult to defend, that A and B are both very hard to defend and don't really feel like their own points, but just points on a map, that C should (imo) be redone and reduced in size.
You're not a bad mapper, this map just has become convoluted. Also, keep in mind that some people (myself included) aren't especially inclined towards this gametype.