What Ocarina said in the video: The walkway from one last point to the other (the ones which doors can be seen in the thumbnail of this workshop item) should be zig-zag, not straight like they are. Other than that, I think it's really cool :D

The part was almost completely unnessescary and has only 2 painfully chokey entrances, and it also makes powerhouse bigger than it needs to be

You could put a spawn door/shutter that opens for both teams at the walkway ochreLight(); mentioned to make that sightline balanced?

I mean, TheSpikedBallofdoom is correct. This area was scrapped for a reason. The new area isn't needed, and it makes Powerhouse worse because of it. The map is interesting as "what if", but nothing more.

Some of the shuttered doors seem to have some issues with rendering things, especially the blue spawn door.
For actual design, the big thing would be adding something for the back end, but you couldn't really do much without changing the map a ton. Maybe it could work as a Standin-style Domination map with 4 points?
Otherwise, a path to the back from the midpoint area might help.