Strangely, you tend to consistently resort to unfair comparisons to present a highly biased point of view.
What KZ was 10 years ago is irrelevant to the direct current comparison of TRN and KZ, who compete in the same market. It is not like TRN sells their IEMs twice less expensive, because they are less established and "still learning".
Sorry, I will repeat my personal observations again.
(I have no any affiliations, KZ/CCA just earned my respect, so I feel to counteract your comparisons that seems quite unfair).
In my direct experience, the quality of KZ (and CCA) IEMs (10+) that I have is just great (no single problem so far).
A single TRN IEM (X6), that I got, has a problem with popping up tips (those provided in their own package(!!)), and then a connector that does not fit snugly, which is both a QC and design problem. Also the plastic of X6 makes it look as a prototype design.
This TRN product is outright not competitive against KZ/CCA, based on these facts.