Typically normal cloaks have no resists. If the item (any item - Vet cloaks in this case) has a time-ingame requirement to get it, odds are that yes ... you gotta wait to use it.
What I would suggest is mess with armor (jewelry, shields) to gain the needed resist points - seriously. I've played this game for some years and never even saw a use for the cloaks ... even when it was simply an Armor Rating (AR) value.