Reduce Double Down to 1 cartridge, reduce the cartridge count back to 2, and increase the range of continuation to at least 5 yalms.

That's really all GNB needs, IMO. The problem with the job as a whole is that they were already so well done in ShB, trying to add things on top of it is always going to invite ire. GNB didn't really need anything going into Endwalker, so anything added on to that kit is going to feel tacked on. GNB suffers the problem exactly opposite to DRK, it was simply too well put together from the get-go.