I've mentioned them somewhere else in a headphone thread, but your posts really make you sound like the right candidate for some custom earmolds. It's not cheap, but it gives you perfect fit which really helps bass performance, and more importantly is comfortable for as long as you want to wear them and doesn't move no matter the activity.
Not recommending these guys, just giving you an example of what they look like and cost. Cost to have a local audiologist do an impression is roughly 100, cost of the custom earmolds is around 150, total 250, and they only fit the specific shape of earphone, so you can't later switch makes easily (but you can switch within a brand IF the casing is the same, like Shure 215/315/415 all use same, Etymotic ER generally all use same, etc):
https://www.pilotstuff.com/averysound/custom-audio-earpieces.html
Again, not cheap, but if your ear canal is a really tough one to find a decent off-the-shelf fit, and it sounds like it is, and you listen a lot, it may be worth the money.