When you mentioned that you need to enable the shader to battles, it reminded me that the background soundeffects on maps wouldn't play during the battles in the default RM2k3 version. Which is lame if there otherwise is ambience on the particular map and you'd want it to be there for the battles as well. Say, if there rained for example.
I don't know if it has been requested earlier, but would it be too much work to enable these for battles?