Reasons for still high r_speeds...
1. no VIS export in first beta, it's absolutely necessary
2. the big not used parts of the map
Done! Light is there, I hope full VIS too. OK now.
3. the box around the map?! The not used area under your map isn't good for r_speeds and should be fixed.
I hope you understood that, because here are very big unused parts. I will help you with three screenshots here.
This not used and useless room under your spawns is way to big. Delete them or make
two smaller ones.
This is another very very big cave under your map. Maybe you don't see it very good because it's black, but look at the pic below (same place)...
...here you can see, that this room is under the whole map. The opening to this area are in lots of places your transparent textures without a sidebrush. "Box around the map" because I thought, that you wanted to fix a leak with this bad cave. Maybe there is another reason for it, but you have to delete it for lower r_speeds.
If you will have a leak after deleting this cave, you have to fix this leak correct. I saw that one sidebrush of this map is a few units to high. Search for black lines in your map or use the leak check and you will find it. Just make this brush bigger.
4. long open area, you can see from base to base, that's a bad structure
I know it's hard to avoid now. But try to find a sulotion for VIS blockers. Maybe you're lucky and could fix small parts with hint brushes. It's often more easy to think about the structure before beginning to map. Afterwards it's way more complicated