tried it back when in this part of the world , saw no advantage to it other than making life complicated ....
as far as shock leader goes , if I am after a fish that might "chew" thru the line , it might happen ....
steel on the salty extra toothy fish is often a must ....
used to use heavy mono in the 20lb. range, when I went after kitty fish with 10 lb. test , they could chew a hook off 10 pretty easily without it .
but as far as crappie ketchn goes , if I use braid, it is straight to the jig .
not many spots have enough water clarity here for it to matter .