If you can make 5B work for you, all the more power to you. But it's horizontal range is less than 2A's, which is why 2A is typically used to get out of blockstrings with. If someone is jumping, I fail to see why 5B would be used over say an actually anti air.
I only brought up crouchers because you said 5B wouldn't whiff on them like 2A would and that isn't likely to happen since 2A is, well its a 2A and it's hitbox was made to hit crouchers.
But after you have used it for some time, please come back here and explain what situations it works best when poking out. I would love to be able to use 5B to poke out of things since it leads to better combos than 2A.