Ok first of all I quite like the B13 changes and the general aesthetic is pretty cool as well.
Generally, my opinion of the map is that it's promising, but still needs some improvements before its on the level of the maps played in ETF2L currently. The two main issues for me are that mid is too small and last is kind of awkward :
-Mid is just too cramped. Right now every midfight I've seen is just an instant DM fest because both soldiers can high jump into the enemy team pretty much unopposed. You can't use flanking routes because by the time you've completed the flank the mid is over, you can't rotate because the mid is too small to do so and your med will die a lot even if you win the mid. Another issue that I did not see so far but could rise is that holding mid looks really simple as every entrance are a stone's throw from each other.
-Last is too segmented ? Not sure if this is the correct word but basically last is divided in really distinct areas with big walls in between them (especially the really thick white wall that's over the point), which makes it harder to apply pressure from one part of the last to another and so a lot of close fights end up with teams on opposite sides of the same wall, spamming. It also greatly limit sentries. Moving the point a bit forward (and maybe slowing down the cap time to make it fair) would be an interesting idea, as teams would be able to play and defend it from more angles than the awkward staredown we have right now.
That said, i think the map has a pretty good flow to it (mid's really small size actually helps that tbf) and second is really really good. You can do plenty of stuff on it, both Fountain and the flank near the truck are useful, its fun to push into, its fun to push out of last, I wouldnt change anything on that.