Cyclops, lets be fair the shield cant defend the entire body of steve, if cyclops does his all out blast it will hurt either steve's legs or his head either way he is not defending against a full optic blast, i know cap can curl like a turtle behind that shield as silly as it sounds but i dont think he is fast enough to go into this position before cyclops simply shoot his beam, besides how will cap even know cyclops is going all out? also cyclops is a master of angles he can shoot all kind of objects to reflect the blasts behind cap or to his sides cyclops did it many times before.
even in H2H situation dont discount cyclops so fast, while in H2H steve will win most of the fights but its not that easy as people believe, cyclops recently gave wolverine a fight after being stabbed by wolverine knocked him off with a back fist to an adamantium skull, cyclops overall got skills and insane damage soak he is no push over even for steve