Note "Proper Retention" in the IDPA RUles Glossary: The use of specially designed pockets, shirt pockets, upper vest pockets, ...is not permitted.
Use of the lower (side) vest pockets is permitted. I do that at times, myself, but it is posible to knock the loader out of a shallow strong-side vest pocket when drawing (oops).
Agree! (IDPA rules, pg 15, para D.3.)
Just remember that you can not carry a loader for use during the stage in your lower vest pocket "at times" unless "at times" is for the entire match. The new addendum to the rulebook forbids changing where you carry in the middle of the match.
3. Competitors may mix carry methods (one in a pocket
and one on the belt) but they must use the same method
of carry for the entire match. Changing their carry
method to fit the CoF will result in a FTDR.