i have a 7hz dioko and i absolutely love it. i would give it a try, since it's not that expensive.

There are 3 different triflange tip sizes, and foamies. Getting the seal right for me is about being willing to put them in deep enough. It certainly takes a bit of adjustment to how deep you have to insert them. There are plenty of non-deep insertion IEMs, but they are "only" usually around -20DB.

I've used the 7HZ Timeless, and it is an excellent IEM... But it doesn't match the ER4, for my use-case.

I know that Etymotics must violate the ear canal to work, but for me the right monitor (and only the right monitor) gets some sort of incorrect seal that muffles the driver after some seconds regardless of the tips used and after cleaning the ears thoroughly, that disappears if I press lightly on the outside, so I suspect a problem with the ear canal shape. I tried swapping the monitors as the cables are detachable, and tried different output devices, didn't work either, so it's not an electronic problem. It's just weird and frustrating. I'm thinking of simply buying a pair of reasonably priced over-ear muffs, maybe with active noise cancelling, and wearing IEMs under them. It would look strange, but comfort is more important.