Doc, man-o-man am I jealous of all the prime meat Costco seems to be taunting you with PLUS at THOSE prices! You must be living right! :laugh:
While I don’t recall anyone posting of aging a tri-tip it could also be that many people do not even know what a true tr-tip is outside of the West coast where it is popular. Besides as I have always heard there is only one tri-tip per cow so it is seldom a cut seen in grocery stores.
Personally I see no reason not to age one except perhaps for the sake of trimming loss. As for length of time to age that, my friend, is up to your taste buds!