and also have a polished slab of granite which makes a outstanding anti vibration pieceI commend you for the tweaks which have brought out the best in your streamer. My 1st efforts in tweaks was with footers. And I studied various materials. I am very leary of granite because it emphasizes the high frequencies which is something my system does not need. If you were having problems with clarity, then granite may be a remedy. But IME IF you want to warm up the presentation wood is a better alternative.
You may already know this. But I thought it worth the mention just in case you don't. That said, if it works for you and you like the sound then that is what its all about
As for a tweak that works, I have my DIY roller blocks/balls under my CDP which adds a lot of improvement to the sound.