/maxmerge determines the maximum connection distance of polygons
Default: /maxmerge 6
The higher you set this var the connection distance longer.

Pros:

Disceasing amount of polygons (wtr) on your map

Possible discresaing output file of your map.

If map big enough it can increase fps on your map (see Examples).

Cons:

Discreasing amount of polygons doen't always mean that it will be the same to your fps. FPS can be lower after this command (- 1-5 fps. Minor influence).

Possible increasing load time of map.

Possible to make fps of your map unstable a bit.

Examples /maxmerge = 6

/maxmerge = 12

/lerpangle controls whether surface normals are interpolated for lighting.
Normals are sampled at each vertex of the surface. If the angle between two surfaces’ normals (which meet at a vertex) is less than A, then the resulting normal will be the average of the two. Normals are then later interpolated between the normals at the vertexes of a surface.
Default: /lerpangle 44

Pros:

Very low size of file. If you can discrease size (20-40%?!) of map why don't use it ?

Speed of light calculating inscreased at least on 20%

Cons:

Possible increasing load time of map

Possible unstable FPS on map (need more tests maybe)

Possible light errors

On same maps this variable doesn't work at all and even can broke light maps