I liked the hf5 from the short demo I made... I recall the extension (or sort of lack of) was pretty apparent though. The BA200 probably has a little more extension than those---or within comparable means. With the silicone tips anyway.
You're definitely right on bright != clarity. The effective range is close to one another to some extent of overlapping so I colluded them together. If we refer to the graph on post #1 (assuming it's accurate) we can see that it does take a dip from 4kHz to 6kHz. As far as extension goes, yes, at times you feel that it might go into the slightly duller/flatter-sounding side of the spectrum. Depends on the music type & personal preference ofc. That is my current problem with my "reference" headphone too (it's flat for most part, but it's also dark sounding).
Most of the time I don't use EQ with them. As I mentioned, those settings are what I sometimes use
on the go (bus/metro/etc.) where sub bass is generally otherwise drowned out, like it or not. The boost is pretty high and that EQ setting gives me headaches when I'm in a more quiet place. And like I said, I do doubt the effectiveness/accuracy of this EQ app. That's around +3.5dB ~ +4.0dB in the sub bass, by the way, and is roughly tuned by ear while in bus/metro.
It only reflects my preferences in those situations for the specific playlist I use with this app, not necessarily to obtain a flat FR.
That said, I don't experience too much sub bass on normal use w/o EQ. As you may know, bass is dependent on your fit/seal. I am slightly in between sizes of the two dual flange tips so that may be the reason why my perceived sub bass isn't very loud. In any case, say I were to DIY something up with my BA200 drivers (which I will eventually be doing), I wouldn't be adding a bass driver but a tweeter or etc. that focuses more on upper/high mids. My subjective view on the extensions is that they're good enough, but I want more clarity. That's kind of what trying CIEM flagships do to you... this is still what I ended up with
That said, I won't go into whether I think you should get these or not... I'm just laying out how my experience with them sounds like.