If you put a gem into the emmiter control option, and release it before it is 100% the emmiters show you as still having some control, This is more a cosmetic issue since releasing it at less then 100% while it shows you having some control you don't and if you let it build up to 100% and release it goes back to being blank.
I am not going to bother with a log or save since it is not a game play issue. But can create either if needed
Cheers