Here via tumblr! What I thought would happen during that scene, and what I think would have been narratively resonant and a creative way around the Soul Stone was that Natasha and Clint would, accidentally or on purpose, both jump at basically the same time, their (willing) sacrifice for each other and the Stone would cancel each other out, and the Soul Stone would be like "you've solved my sacrifice riddle!!!" Because it never made sense to me that an unwilling sacrifice would work for this. Like, yeah, sure, lose what you love, but I feel like if what you love is not down with you chucking them off a cliff, your sacrifice isn't worthy of the Stone. I also thought Infinity War set up something potentially interesting and plot relevant by having so many of our heroes willingly, deliberately sacrifice themselves for the Stones: Dr. Strange, Vision, Gamora's initial willingness to die so Peter could get the Reality Stone, Loki, etc. Having Natasha and Clint subvert that, having them find a loophole or show that in loving, willing sacrifice there's a path to transcendent victory, would have been far more satisfying than what we got. Of course, I suspect this would have been too sentimental and not edgy enough for most of the higher ups involved with the movie.