I did notice my K840 ping a bit but not to the point where it would bother me. Though I wouldn't be surprised because Romer G has such large springs.
I haven't try this yet but for something simple and cheap to start with is to try putting things under the keyboard see if it helps.
Back then I used to put towel under the keyboard to absorb desk echo, you could try that or something kind of deskmat or mousepad and see if it helps.
If the above doesn't work back then we also tried putting drawer liner into the keyboard (felt cloth probably works too) to dampen keyboard noise, this wouldn't be too hard to do either but require you to open up the case and which might void your warranty.
Though in general it's not too hard to open up a keyboard.
Lube all the switches will be really annoying to do because it will require you to desolder all the switches so if we can avoid that route I'd avoid it.
Let me know how it goes!