i think your question of what is the difference between the function of liver bile vs gb bile is a great one. i don't know the answer. and once that gets answered, the whens of each release would get answered too. form always follows function. would you consider posting it on the andreas forum? he'll know the answers to both (or all 3) questions. in fact if i see his forum open, i hope it would be ok with you if i asked him your questions. i'm a curious sort as well.
One thing you said got me. on this last flush i got absolutely no stones out. and just like you, i didn't take any epsoms salts on this last one. i also found, like you, that recovery time was reduced, and for me, nausea was completely reduced. but.. i just wonder - did not taking the epsoms salts account for the no stone part? the body is so knowing, and if the ducts aren't big enough to let stones out, i wouldn't be surprised if the body already knew that, and acted accordingly by not sending out the stones. wouldn't surprise me if this were true.