I removed the dampers from the XY motors to see if they were contributing to ring or overshoot - I didn't see a difference in the print, FWIW ... but the increase in noise level was minimal. I have replaced all the small, noisy fans with larger units - so the fan noise has mostly been addressed.
I don't expect this to be a hot topic because I'm sure heavy cast iron plates aren't something most folks have on hand - but you might try something like a large concrete patio block to put some isolating mass between your printer and whatever it's on.
