I doubt that connecting the electrical contacts without soldering will preserve your warranty. Bypassing this soldering step with the intent of unethically circumventing the warranty details (to which the customer implicitly "agrees" just by buying/using the product) is a simple enough thing for Asus engineers to devise on their own, and detect, and counter. Failure to do so would cost Asus money (on products damaged by non-accidental customer modification and/or out-of-spec operation), and it would be a perfectly legal (even expected) way for Asus to protect themselves.
I suspect the card's firmware will still (permanently) flag some hidden/internal/irreversible LN2-was-enabled "evidence" which Asus would routinely check on every returned card. Physically soldering the connectors is probably only necessary to ensure the most reliable electrical signal (whatever that's worth on a simple jumper, lol) and, more importantly, to provide indisputable visual aftermarket confirmation for those of us who don't have access to Asus's proprietary engineering secrets.
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[/Korth]