Well Charles....very little if any information is published on the science of ballastology. The pros are even hesitant to lecture on the subject as it falls into the realm of Boson Particle Theory. I actually thought you were asking about etiquette while dumping water in a thermal, reading your title.
I feel the general opinion is to learn and tune your skills by being out on course. Intuition plays into it followed by Monday quarterbacking after the flight if you’re not the winner. Your best bet for information is to research who the big dogs always seem to be and call them up, get their feedback.
Try here and the thread will drift over to hook releases or lithium batteries.
Cheers,
R