The BeastK-2 would wedge more because you'd have a more obtuse primary grind if you only reach the same grind height. If you applied the same primary grind angle as on the BK9 to a 1/4" thick blade, you'd be much closer to a FFG.
Hard to describe in words, and I'm having picture transfer issues.
Imagine in cross-section: The BK-9 grind angle becomes flat at height X because you run out of steel thickeness to grind at at 3/16". If you had 1/4" thick stock, there would still be metal to remove further up toward the spine before you ran into air. So the natural grind termination would be higher at the same angle.
ALSO, the BK-9 is a taller (wider) blade than the BeastK-2, so at the same grind height even in 3/16" stock, the BeastK-2 would be wedgier.
Basically: where the grind stops as it goes up the blade is a secondary result of geometry decisions, not the primary input to the geometry design.
If you like the geometry of the BK-9, but want the 1/4" thick spine, you're going to end up with a higher grind, all else equal.
If I were MAKING such a thing, I would target the grind to terminate at the spine - FFG - and just decide to be happy with the resulting geometry, since it would be a decent and attractive compromise. Would have to do a bunch of measurements and trig to compare the angles exactly, and that's just not a thing worth doing, IMO.