I am not sure I understand your OP then. I know it is a Fed mechanic and required in NJ. Others in your group are resisting it? If so who is evauluating, your group or the state? If your group then changing as a group shouldn't be a big deal. If the state then I don't understand why your cohorts would resist, it's in their best interest.
As far as when to release, I would say when the runner has committed to third. The tricky part is knowing the right moment to release, deciding between a possible rundown and a honest advance.
It would look way worse to release and then all of a sudden the runner stops and you have a rundown with the BU running away. This is why it is a bad mechanic, too much can blow up, too much running with no advantage. It is a throwback to always an umpire ahead of the play, the problem is by releasing too early has the exact opposite result.
If the BU takes him all the way to third and the throw is bad, now you automaticly have that pickle covered. If the runner tries to go to third and gets hung up between second and third, the BU has it all initially and the PU comes up and gets his end when he can. The other way, you end up with the BU at the plate and the PU at second.