FH7 is very detailed across the entire range. But strong lower treble elevation creates a
masking effect - preventing people who are sensitive to that lower treble frequencies (and possible peaks, that I don't see on the graphs but from experience assume they're there) - from hearing the treble extension.
Reducing 4-8K with EQ may open up that extension but most EQ apps don't do it correctly. I use foam filter that I put in the tip in front of a nozzle. (No space inside obviously) It worked for me the best - with Noble M3 and Mofasest Trio, where this problem is worse. It also worked with Penon Orb, though resulting in overly dark sound. Typically, good mode for overly bright IEMs. (Like FH7)
For me, any IEM that has too much 6-10K would sound like upper treble(12-16K) is rolled off. Masking effect is like blinding bright light - preventing from seeing details in the shadow.
https://en.wikipedia.org/wiki/Auditory_masking