Hickory needs more spine. I shot 70 pound hickories out of a 55 pound bow (maybe this is 5 pounds different than the cedars I shot). This was with a riser cut in a pretty traditional manner (not past center, or even close to center for that matter). The math is that more weight is bending around the riser, to recover it takes more spine.
If however the bow would be cut to center, or past center I would guess the effect would be much less. Note thought that usually bows cut to center or past, shoot stiff spined arrows to begin with. I've never shot hickory from my widow, but I'd guess the effect of spine would be less dramatic with it than my longbow.
Try them. They are durable as all getout. I didn't break many,the ones I did usually were direct hits on rocks, and even then they didn't always break. Try them, If they don't work, put some flu-flus on them and use the for close rock killing.
Aaron