a good vis'd map can also be burdensome in other areas too.
take that triange pic above. If a speaker or target_location is on the other side of that triangle, you won't hear it and it won't show up. Not a big deal, right? Cause you can just put it in the triangle itself and it'll be visible to everyone.
But if you are on side of the triange, a marine is on one the other side of the triangle, fired his grapple to a spot inside the triangle, you would hear the impact from the grapple but you would also experience the 'defense's best friend' grapple effect, where the grapple would be drawn from the spot to the world origin. (Think of 2fort's flagroom where you can see all grapplers as they are approaching the flagroom from top of ramp or elevator)
If you toss a grenade and it lands on the other side of the corner, you will never hear it explode. (think of 2fort's top chute).
So alot of testing needs to happen with vis. One of the easiest things to do is just turn it all into cement, after you are done your caulk hull, and just run around after a bsp, vis only compile and mess with ur ents or start building depots, dropping decoys, etc to see if they are still 'drawn' with r_showtris. Then just do a search/replace on the cement back to caulk.