Cote Dazur
Addicted to Fun and Learning
Guessing you are new to IEMs, I was too, not such a long time ago. Let me help if I can.2nd listen with 'phone inserted to maximum extent possible ... definitely better but still noticeably bright and slightly "honky" sounding ...
Everyone is obsessing with the FR curve, FR is of course important, but how a particular IEM fits in your ear, and we all have different ears, is much more important.
No need to push them hard, or deep, actually it will not help.
What you need to achieve is a "seal". When new, a good way to know you have a seal is that you should ear your respiration slightly when no music is playing.
2 important aspect for good seal; One, the size of the silicon tip, try them all, one is going to be better. Second, the angle at which, the nozzle seat in the ear, that is key. just placing the IEM flat in the ear, may or may not work.
I was lucky, I started with the Zero blue. the angle was almost perfect for my ears, so I got great sound almost from the get go with minimum fuss. my second was the Hola, that is when I found out about the angle. My third are the Zero2, if did not have known about the angle, I would have returned them scratching my head on what everyone was raving about. They fit my ears the less naturally than the other 2, but when correct, they are as great as the FR suggest.
It seems daunting at first, but as you get experienced, you will know almost instantly, when they sound right or not and correct the sitting in your ears in seconds to extract the amazing performance, these IEM are able to produce.
Burn in is not the answer, but you already knew that.perhaps they need some of that supposedly unnecessary "burn-in"