I think that the Bk9s width is what makes it unique.
1/4" thick 9" blade is by no means a prybar, not is it really even that thick to be honest. Wouldn't be that heavy, and generally might not be what you expect.
The blades that I have become used to are nearly a half inch thick.
With that being said, to make the Bk9 that thick slice and be as useful as it is now, the grind would be have to be brought up substantially, probably to a ffg. Otherwise it would become a brick like a Tops.
But to make the Bk9 1/4" thick and ffg would completely change the knife, and essentially make it a shorter RTAK II/ Junglas.
Problem is that 9" is too short to take full advantage of a blade of that styles geometry.
It's all a balancing act. The Bk9 isn't the giant beast that it has a reputation for.
I learned that while comparing it on my YouTube channel against a bunch of Ontarios and a Khukuri.
What the Bk9 IS is a wonderful balancing act, that almost perfectly mimics the strengths of Ethans handles. It is special imho, as is the bk4.
As a new knife designer, what I REALLY want is for the thumb ramp to be moved forward 1/2", and a choil to be added... But hey, when it comes to designing, Ethan >>>> Jacob lol