Yes, there is a developmental aspect to laterality, and almost no kids at the end of second grade reverse b-d (I have only 2 that occasionally do it in Gr.3, and none do in Gr.4).
Because it is developmental (like tooth eruption, for example), work on it bears little fruit until the child is ready. That said, we are doing things that allow it to happen… IF they are ready.
Examples would be:
(1) Circle all the b’s on a paper with random letters on it (Tracking Drill)
(2) Overlearn b, not d. Post a blue bat and ball on the front wall, toward the left hand side
(3) making a “bed” with one’s fists together, thumbs up
(4) putting a bracelet on the left hand
Also, at the top of every Gr.2 paper is a b with a bee next to it on the left corner, and a d with a dog in the right corner. We’re not even concerned about reversals until then.