YES. Finally eke has achieved proper ety bass levels! This is actually really exciting.
The bass is pretty close to an all-or-nothing deal depending on fit, and fit is not at all easy. In fact I'd say ety's are the most difficult iems to achieve proper fit that I've ever tried. And actually the ER-6 is worse than the hf5 and ER4 as far as reaching the reference plane. And even once this mythical fit is achieved, the pain is almost too much to endure. I'm surprised anyone ever stuck with ety's long enough to find out how great they sound.
Your knife-in-the-stomach analogy is perfect. As long as it doesn't move you'll forget it's there. And after a few months you can even move it around quite a bit and likely the ear will have adapted to the sensation, and it won't feel painful anymore. Now what I do is insert just past the second bend, wait for the tips to warm up from body heat, and then push them in just a bit further. I find the tips become more pliable with warmth, and they form to the ear better.
It would be great if you could find tips that allow a more comfortable deep fit. Foams don't work for me (they may for you) because they don't go deep enough. If you have an extra pair of triple flanges I'd advise cutting the smallest flange off the end, wetting the tips, and just going for it with a slow twisting motion.