I really like this map's style and a lot of the gameplay spaces the map offers, but I feel like this map has some really deep fundamental flaws that really eat away at the experience, a lot of times this map is either a complete lockdown for A or B, or just a total roll because you have to defend this map in a very specific way.
It has now been twelve versions and the map hasn't really improved all that much in my eyes, so I thought I should go into in detail what I think is wrong with the map and suggestions how to potentially fix the issues without reinventing the whole map.
Let's start with A, where these issues right away raise their head.
A has a really cool gameplay space to fight in and when you first enter the area as RED, you are right away greeted with spaces that seem natural to defend from once the forward hold falls. Unfortunately because of the way the map is currently, holding where all the ammo and space is, is actually almost always the worst way to defend. That is because blue has a route that entrance is disconnected from the area that goes all the way around the point.
Because slower attacking classes have very awkward rotation to the upper areas from the cart route and the flank is right here, holding the dev textured platform and the small room next to it feels like almost the only effective way to prevent BLU from overwhelming the defense and starting to roll. Since these are the only two routes BLU really has, this tactic also usually results in BLU being totally stonewalled from A in a very frustrating manner if the defending team puts all their focus in this area.
In the instance RED doesn't put all their eggs in this basket, this route is extremely broken if BLU chooses to abuse it. Not only does it place players using it out of the reach of the platform overlooking the point, it continues further and bypasses the A point entirely, effective allowing players to either get directly behind the defense or skip A and go to B and the enemy spawn.
Because of this, defending A doesn't feel very dynamic or fun, the map is basically forcing me to play one way and gives BLU a very annoying way to abuse the map if I do not. My suggestions how to fix this and hopefully make the point more enjoyable and varied experience are as follows:
Improve the rotations from the cart area for BLU, right now it is very awkward to be in the area where the cart goes through and try to move to the higher ground or switch your positioning towards the flank. If RED pushes either route with an uber, you are usually forced to retreat in one direction and in a relatively straight line. Also make the wall in the tunnel chickenwire so this isn't such a blind turn for either team and you'll see the pushes coming as the attacker. These changes should make playing in this area less of a chore and nerf the dev texture spot moderately, so it isn't so shutout inducing and easier to play around if that is where RED chooses to hold.
In exchange, I think you should remove the big flank that goes around A entirely, it is a waste of space on best days and map breaking on the worst. I think it would be more dynamic if this area allowed blue to gain equal or relatively equal height to match red's on the other side of the point, a bit like C point but better. (I'll get to that later on.) In theory, this should focus the fighting around the point, prevent non-flanking classes from easily getting behind RED and be overall improvement over the current A.
B has the same problem, although it is not as bad as it is at A and it just might be a byproduct of the flank at A and A usually being a roll when blue isn't totally shut out, but it is still something that bothers me. If RED doesn't get a forward hold right away after A, in many scenarios I have seen a medic combo flank around onto the high ground above B before RED has any real defense set up and are still recovering from losing A. Even in the event it doesn't happen, this area feels very awkward to hold and build sentries in. Often a demoman can sneak into the low ground and pipe the nest without being seen by it and it makes the area bit awkward to fight in, in general.
I wouldn't change much about B as it is right now, the two suggestions I have are as follows:
Even this area up and reduce the flank to the one of the two door (You might have to rearrange how the inside is laid out) to make it more specious to fight in, there is plenty height variance around already so this feels like a bit of an overkill, flat space isn't always bad.
This route is also really awkward for both teams, neither team has a very natural approach to it and I am not sure how RED is meant to hold it and it doesn't feel very good to approach for BLU through either route to B. I think a doorway would probably be simpler and better for the flow.
Now on to my both favorite and least favorite point on the map. I love C's general design, it looks cool, it seems like an interesting playspace on paper but most of the time RED loses control of this area before they can ever hope to get control of it because blue can access the highground over the point before RED has any form of concrete defense set up.
This is because the entrances to the flanks start far, far away from the point and only way for RED to control them is to either go the flanks themselves, which are not very good positions to defend from and usually takes too long, or push far away from the point almost back to B. I know these are set up the way they are because otherwise only way BLU has into the would be seen from cliff right above the doorway.
I would turn the current cliff opposing the cliff BLU likes to use into an inaccessible area (Cliff, building, whatever) and make the other cliff into the main defensive area RED uses, then close up the long flank to the lower path and bring all the routes closer together. This would be more cohesive and in theory give RED much better control over the area and make the point layout in general feel much less janky.
I had thoughts on D point also but I saw some of the changes there had fixed few of the problems I had with it in the past, so what I was going to say about it is now null and I'll have to play the point more to have an opinion on it again. Please keep in mind that you don't have to realize my suggestions exactly, they are just food for thought more so than exact directions on what to do, I hope this post has helped.