I find myself doing it more often, i.e. letting the hands help out each other, if it makes it easier or helps to improve the result.
And it's not just you/us, but also the famous pianists, I guess. As I learned Schumann's concerto, I always found the long descending passages which are described (at least on the Edition Peters) as being performed by LH alone very difficult (like one on the attached pic). But I saw on TV Argerich play those passages also with RH helping LH, I was very surprised. Before then I thought the famous pianists don't need change anything written in the score. But it also may be the case that the score Argerich used to learn that concerto dictates it, since I found later that it is written so on the Schirmer's edition.