Thanks a lot for all the insightful replies, that mod is very inspiring Ivan, I might just go ahead and try it myself, I have a feeling that, also nudging the plate in several places, like damaging it by nailing it, might prevent the vibration from retaining
It's pretty much like trying to prevent a bell from not ringing, not an easy thing to do, the reason I don't want to resolder is because I'm very tired and don't have much energy left for keyboard mods at this time, so an external solution was more appealing
As an omitted background information, I've desoldered, modded each switch, also stuffed the case with whatever material I can find, and still experienced the issue, when the switch pings were all (all but 2) eliminated, the remaining unwanted sound was the strong ping of the plate, especially on cherry mx green bottom-out's, the ringing of the plate was unbearable
I've since settled on my red-switched board, abandoning green switches altogether, even the red-switched board is pinging, yet it's more mellow and unobtrusive
Like you guys mentioned too, it's possible to mod the switches one way or another, yet the same doesn't apply for the plates, I'm hoping the steel plates of the infinity keyboards will be ping-free
(I just repeat myself all over the place, but, also the red/blue/brown switches seem ping-free to me, as their springs have high coils, I couldn't get them to ping individually, which is just great)