i would just like to say that your map is very good as is. i wasn't able to find very much to critique, nice work.
i feel as B doesn't have many places to hide. you could possibly open up the hut on B with a doorway on either side to allow people to enter it similar to the one on cobblestone. i'm not sure about making it so it can be shot through though, that's up to you. also, this is just a suggestion of course, don't feel obligated to make this change because someone said they thought it was a good idea.
second, small complaint here, consider adding a clip brush on the truck on A. i found the top of the truck to be finicky to walk on considering it's not flat, even getting myself stuck a few times.
there's a spot on B where you can stand that let's you you see the main T entrance to B with little of yourself showing. i'm not sure if this was intended or not but i definitely don't think it's a fair spot nor should it exist.
the building that CT's come from when entering A site have large windows above the doorway. from the inside, you could boost a teammate on your head to see through the window and for the most part, entirely see the A bomb site. i don't have a solution to this without entirely removing the windows themselves.
below is an image tying back to the spot on B that lets you see on to main T entrance of the site because i feel like it would be hard to explain the exact point of which i'm speaking about. as well as a short video of myself finding a few ridiculous places you can parkour to which should be patched up with some clip brushes.