those numbers are intimidating! personally, i would stick to what's already there, since they're presumably set by people with spectrometers who, i hope, already figured out what works best. i think they're also preset on all or most of the piano patches.
i'm curious about the mud... on my Juno, most of the pianos are too bright IMHO. maybe our monitors (or ears!) are that much different. you could try a little 3-4k on the EQ or higher (hard to tell what you're hearing). my reverb suggestion is moot, since you want to clean up the mud.
however, i think a different patch or the piano SRX may be in order. sorry i don't have a great piano to send ya
EDIT: now that i look at it, it looks like tweaking the Sympathetic Rez is probably a good choice. however, i am not qualified to make suggestions there (or apparently anywhere, come to think of it). very sorry!