Below is a Modulemanager config that can limit (or raise) the science gain per experiment type. I've not tested it a lot but it does what you expect and I can't imagine it causing any other problems. If it does, please let me know and I'll see what I can do. However, it's a very simple config. Just copy the text below into a *.cfg file and put it in your gamedata folder, or any folder off of your gamedata folder. The below config limits ALL science gained, though Surface Samples are still worth