couple suggestions, as I had bad layer lines on prints just using a dual z setup without these:
Increase stepper current in firmware, this is pretty much a must unless you have individual control of each stepper motor, more than likely they are controlled by same driver and are sharing current depending on your board.
Ditch the blocks on top, this accentuates any wobble in the rods.
the above might be part of your noise issue
and this last one was a major factor, and has nothing to do with your noise but definitely the biggest improvement to quality,
Get a linear rail kit, they sell ones on amazon that are red, they aren't compatible with the x tensioner on the v2, but if you replace that x tensioner with a generic one, they fit fine.
I had good luck with these:
https://www.amazon.com/dp/B09BRBK3NK
these are the rails I used, both slid freely without cleaning on arrival (ofc, clean them and lube them proper though)
https://www.amazon.com/dp/B0762MKQFD
and x tensioner:
Good luck, about $85 worth of stuff, but worth it.