key chattering on k95 rgb platinum

Hello.

I've purchased a k95 rgb platinum, brown switches with an italian layout, off of amazon.it

I've also bought the double shot pbt keycaps (which don't come with all-italian keycaps but that's another matter).

Have been using the keyboard for less than a month.

I am using the latest firmware through CUE.

Have started noticing keystrokes being registered twice. "E" that I can remember, at least.

Have done some research and got to these forums, where I troubleshooted using the Switch Hitter software and trying to lower the keyboard polling rate on the CUE software.

Have tried pushing buttons fast and at random on Switch Hitter until one would light up as red.

First question:

how am I supposed to test on the Switch Hitter exactly? Do I press keys randomly with the same speed I would normally, or do I go superfast, or do I go and press multiple keys at once with my full hands? Cause in that case I get red keys pretty easily on Switch Hitter.

Second question:

What does the polling rate do in this case exactly? If I lower it to the minimum and have the chattering not happen anymore, what do I lose? Performance?

Third question:

Is there more troubleshooting I can do?

Fourth question:

Do I send it back to Amazon for replacement (which would be fast and free) or do I send it back to Corsair?

And what if I get the same issue again? (not too unlikely, judging from some posts)

Thanks in advance for any useful reply, I had specific needs for my next keyboard and, although I would have preferred blue switches, italian layout was a must among other things.