I know that the Shaare Efrayim and Igros Moshe say that the congregation should start saying "B'rich Sh'meh" when the Torah scroll is removed from the aron (cabinet). Are there halachic opinions that "B'rich Sh'meh" should be said before (or should culminate with) the removal of the scroll from the aron? (Sources, please.) If not, why might so many congregations do it that way?
(I'm referring specifically to Ashkenazic congragations and halachic sources.)