ABX,
You are spot on in your thoughts.
However, it has been known, for the odd tanker in the heat of the moment, to not want to change levels / tracks / routing for fear of complicating the rendezous or because it's just too much hassle or they lack the confidence to make such bold decisions in the vinegar strokes, despite it ultimately being a more sucessful AR because of it. My opinion of sucess is a safe join, an efficient offload and smooth breakup. Being on the planned route, no matter the costs / weather is not important.
US tankers much more so than UK one's I hasten to add. "Black-line-itis" can be a compelling infliction......
(Not all tanker pilots sit in the weather. But some have, some do and some always will..
)