Being able to use more baits per tap during fishing would definitely make manual fishing more meaningful. Ideally through tower artifact, farm supply, perk and meal. Each would unlock additional +1 bait usage, but can be toggle on and off.
Large Net already allow us to catch 550 fishes per tap, the only downside is not being able to get gold fishes and super rares.
Even with the ability to use 5 baits per tap, with cat meow active, on a location where the fish are biting. We will essentially just be getting 35~60 fishes per tap. That's just 3 to 6 fishing nets.
This improvement to manual fishing is not severely imbalance considering we can get much more Antlers exploring Forest with Arnold Palmer or Cider, crafting those Antlers into Large Net would most likely get us more fishes with less time invested.