You can easily adjust the caustic intensity by adding
lightmap*=0.5;
in the shader code before line 153.
You can also remove the caustic effect completely and improve the framerate by removing
float4 lightmap;
lightmap = tex2D(sLightMap, 0.5*vecSkill41.w*OffsetTex+(vecTime.w/300))* tex2D(sHeightMap2, IN.Tex);
lightmap *= tex2D(sLightMap, 0.5*vecSkill41.w*OffsetTex-(vecTime.w/200))* tex2D(sHeightMap2, IN.Tex);
from the shader code and changing line 154 to
(0.4*color)+