Board Thread:Theories and Speculation/@comment-27717552-20160513151229/@comment-734582-20160518104435

Actionmanrandell wrote: in reality if minato/kakashi, jiraiya wanted to add an element to there rasengan they could in fact easily do it. Even that stage took Naruto a considerable amount of time and effort. The fact that nobody else did it suggests that it's not at all easily done in any way shape or form.

Not to mention, having to form the shadowclone and preparing the technique that way has always been a huge weakpoint. Minato's speed-based techniques would never allow for such a style, and even Jiraiya entering Sage Mode was problematic against a strong enemy. Standing still and forming an elemental rasengan is simply not worth the risk of a bit of extra power.

Even Naruto never used Wind Style Rasengan because the extra clone wasn't worth the small increase of power.