I made a note about this in feedback today, but the flank you have that goes behind A is really just a problem route. It doesn't really solve the issue of A being a tight, cramped space with low visibility for blu. All it does is mean that A is a guaranteed cap every single time the map gets loaded up. You need to lengthen the route to A somewhat, and make it easier for blu to not get spammed out no matter where they are. Every doorway for blu is a blind corner from which a sentry/explosives can fire freely, and it's just a grind to push through. I highly suggest working a slight redesign of the area around A into the changes you're planning for the middle of the map. Blu pushing through each time doesn't mean it's fun or interesting.
It's good you're going to redesign the area around/after B, I think that's been the worst area since A1 or whatever version I first played. The fact that it's just a huge sprawling flat area makes it kinda boring, and the flanks all wind around and through each other up to C (and then after, a little) which means there's not really a front to defend and blu has an easy time rolling through. I think if there was more of a hard turn between B and C, and less sprawling flanks off to the side, it would probably be more interesting.
I'd like to see the space around C and up to the final turn into D not be so much of a straight line. I dunno if that's a contest entry thing, but it kinda sucks right now. I've noticed a lot of your spaces are very tight, even around the cart where you normally want to have more open areas. Try to avoid that. The cart path should be the widest, main path, but right now that's not often true. Not only does it make it too easy to spam out people pushing the cart, but your flanks are for some reason often way wider than they need to be. Generally your map is a lot like Barnblitz but even tighter.