You'd have to build up a lot of plasi dip to create enough thickness around the bracket. That would take forever, even if you globed it on (like I do).
Then you better make sure you don't need to go back in and take that cpu out for quite a long while or all your work is down the drain. Actually the first time you need to swap cpu's etc, you ruin the whole job, because you just can't pull up a portion of the dip without possibly compromising the rest of the mobo cpu "area"
I don't think it would work very well.