From what I understand, as awesome as an inventory Bait tab would be, SE is reluctant because they wouldn't be able to add a bait tab JUST to fishers - EVERY player in the game would get the bait tab, and the vast majority never bother with FSH at all. It would be a humongous amount of reserved space that's never actually used for anything.

Folks who manage databases for a living simply cringe at this kind of thing, and I'm guessing those folks at SE are no exception.

SE's current solution is for FSH to use the same inventory that everyone gets. Not particularly fair to Fishers, to be sure, but it is what it is. It certainly doesn't hurt to ask for more, but I unfortunately doubt this will ever be a thing.