You're missing the point. Taking apart an IEM and rebuilding it is obviously NOT impractical nor expensive as you already do that process during ownership transfer for only $399. Why can the same process, with the added step of replacing the drivers responsible for the 20-40hz range in both ear pieces, not be done for an out of warranty repair, for 399 + cost of drivers + labour?
Irrespective of that, you're not even willing to offer advice on how to diagnose the issue. I have loved my K10 CIEM since I got it in 2014, the sound signature has practically been perfect for me and it's held up really well. I fully understand that 6 years without any issues is testament to the build quality, but it was a significant investment that I'm not likely to be in a position to make again for a long time yet. So I think it's only fair that I should want to look into ways to continue enjoying them, other than purchasing a whole new CIEM. Yet your response is to mock me and tell me my only option is to buy a new set. Why are you not willing to have a discussion about options? If a new purchase is really the only option, then I can settle with that, but at the least there should be conversation and some troubleshooting done before that's the conclusion we arrive to no?