It's a bit thin for what most people use large knife such a BK9.
I think it would benefit from added 1.5 oz or so (that's about the difference in weight between 0.188 and 0.210).
0.022" increase in thickness wouldn't decrease its cutting ability by much but it would help quite a lot in other areas.
I used to think like that, but honestly I disagree at this point (respectfully of course, everyone can have their own opinion, doesn't bother me any).
I've owned my BK9 for... 4 years now? At first I wanted a 1/4in thick version. Then I noticed that it doesn't need to be any thicker (for how I use it at least). I rarely baton anything > 6in, and even then I try to choose nice straight grained wood for the ones that get batoned. And I've never once saw a bend in my BK9's blade using it like that (I did get it to deflect a tiny bit earlier on in a ~5-6in heavily knotted piece). The BK9 was also the knife that made me realize that I don't really have a need/use for a 1/4in knife anymore, as if even the much longer BK9 (meaning, longer than the BK2) doesn't bend/show signs of struggling with 3/16in thick stock, then 1/4 is just overkill, ESPECIALLY in shorter blades.
I also don't chop much with it (anything over 4-5in takes too long, and I'll just use my folding saw), so extra weight doesn't appeal to me that way either.
And finally, I am fine with the skeletonized tangs. They should be just as strong in the same axis that the blade is strong, and reduce weight. The only problems I've ever seen with the skeletonized tangs, is that the HT transition happens there, which I'm not exactly convinced is the fault of the cutouts (vs the HT transitioning), but I don't claim to have seen anything.
Anyway, I'm fine with the BK9 as is. If anything, I'd be fine with a drop point, FFG version

.