Fisher's and retainer's gear melds

[Alx789]

I heard that gatherers gear is not always BiS for both. Fisher doen't needs GP, retainer needs Gath only.
I heard that i70+ gear and gevel can have greater caps for gathering materia melds than default gatherer's BiS.
So, for fisher it's probably interesting to replace and meld all jevel (gp stats in gatherer's one only), for retainer - all items w/o Gathering stat.
Anyone tried to do this? Which caps?
I think that the most interesting is i70 crafted items (lazy nq craft) and maybe i90 nq