I mean that you can decide the reactions of ALL the Elements. And how they react to each other. I made this post so you can better understand what I'm saying because I'm bad at describing things.
Thanks for your feedback! I made a simulation similar to this one where you can make your own reactions. Click on universe assembler and type something like
p0 p1 -> p4 p5;
That will turn type 0 and 1 into 4 and 5. So you can set all the reactions yourself.
Download it over here: