Mechanically it'll be fine. I've been bolting heatsinks down watercooling-style since I first saw a water block. M4 screws from behind the board with a nut & washer on the other side to hold them in place, slide the heatsink bracket down over the screws, another four nuts and you're done. Should use springs really but I never seem to find any.
Some risk of cracking the die if there's no supporting material left around it, but about the same risk with a waterblock. I'd be tempted too.