Yeah I had something like that in mind, will try with some foam sticked to the heatsink.You could always put something insulating in between the heatsink and NAND. Even a couple layers of paper might be enough to avoid them getting noticeably warmed up.
Waiting for a proper M.2 length heatsink to arrive, so that it will stay centered above the M.2 drive. I just hope it will be as much efficient as my home made one...