It's possible for nvidia to replace the resistors with one-time-programable memory ,and program it at factory. And it's cheap, it's being used in $1 FPGA from silicon blue.
I don't even know if they'd bother to do this due to the handful of people who are actually going to buy the gaming card to make it into a pro card.
Most people who are probably doing this are hobbyists at best. Most professionals would probably just have their company buying the cards anyway, and this hack won't at all change that.
Actually, it being a hardware hack rather than a software hack makes it even less appealing even for small shops to try. "You want to take that new $400 video card that we just bought you and do /what/ to it?" vs. "ooh, it's just a software upgrade" (even though both have the very real chance of bricking the card in inexperienced hands).
And they'll probably do this in their next chip.