Anyone?

There are some, but they're nothing special. At least the ones I tried. Gaming headphones, all of them. Maybe somebody else will chime in with different knowledge.

It does, yes. It provides the best 3D effect i have tried, not having tried Realyzer. It's simulated, obviously, but the effect can be quite believable. Better than multidriver headphones I have tried.

What do you mean “they slam”?

Found Sky Audio Cables in the UK but I’d rather avoid the hassle with custom duties…

I'd like to introduce you to that £$%#$£ of my left ear canal Yes, that's the way to go, I concur.

Nothing like this exists?

I don't think Foobar2000 offers a parametric equalizer without extra software installed.

I suppose EqualizerAPO (with optional Peace GUI).

A question. Since I am in need of a new pair of CIEMs, I'm eyeing this product. Nothing super-fancy, probably, but the fact that the company is based in my city means I will be able to pursue that elusive and so important perfect fit. I am currently using Fiio UTWS3, for which I heavily modded...

Wavelet allows for personalized EQ settings, even though the process to add those is a little bit involved. I suggest you give a strong look at it. It's free, it works great, what more could you ask?

Interesting from an engineering point of view, for sure. After 15+ years of CIEMs, I'm pretty convinced that the most important aspect is how they fit. There's good fit and then there's perfect fit. If you don't get the latter... there's not much engineering can do to help.

I hope you are right. With an HTPC they're still the best surround emulation I've found. Too bad they can't handle Atmos and DTS-X.

For a product that works only when connected to a USB Port, the battery being necessary for it to work at all is... surprising to be generous.

I had good results as far as comfort is concerned with these: https://www.amazon.it/dp/B0842HY2KS/ (found them in black when I bought them some time ago).