pixelphoto, thank you for your comments regarding the Schroeder Method. Your post is important for a few reasons; you are not in dog fights here, but are an occasional poster who is not fighting for ground, so to speak. That may help others see that it's not a matter of who can debate the best as to the legitimacy of it.
Looking at your system, please do NOT take this the wrong way, you have lovely entry level equipment. You are hearing the improvements clearly on equipment that is not SOTA (state of the art). That is important, because it confirms what I have known for many years. One does not need extreme equipment to hear the benefit of cabling changes.
You also have achieved the good result, very clear unequivocal result, with inexpensive ICs. I trust you will hear very distinct differences using a variety of splitters - I do.
You said a very important phrase, "I'm glad I kept an open mind." Yes, you have benefitted for having that openness to try something that likely caused a certain amount of doubt. Congratulations on being an explorer and finding something much better.