A simple tube pre amp from aliexpress with treble control is the solution for you specifically for more warmer sound. From what I read from your posts you will go mad if you hear titanium tweeters
I have the Taga 6.5 bookshelves and use the said pre amp to control treble. High treble doesn't mean the speakers are bad and these are the professionally tuned to be flat? Though it may be possible that your unit may have had issue also sometimes a break in time is required to judge the speakers.
Also, I got them for 4.5k, just the class D amp and pre amp costs more than these for those into DIY.