Dignity for Utility's Sake

The more we read and discuss Mill and his interestingly nuanced version of utilitarianism, the more I cannot help but wonder if he secretly (or subconsciously) harbored deontological views regarding the dignity and inherent value of all human beings.  Not only did he use words like dignity fairly often, but he also seemed to work very hard to bend and tweak the principle of utility so as to incorporate such ideas.  Both his attempt to distinguish higher pleasures from lower pleasures and his incorporation of rule utilitarianism seem to suggest that he wanted a utilitarian basis for ideas like dignity.  Even if it is (and it probably is) wrong to suggest that Mill was a closet Kantian, though, I find it interesting that we could almost take his brand of utilitarianism to an extreme, where we would find ourselves knee-deep in deontology.  For instance, if we were to use rule utilitarianism to suggest that, in the long run, utility would be maximized if all people respected the dignity of others, and treated all other people as ends in themselves, couldn’t we essentially justify deontology for utilitarian reasons?  The convenient byproduct of this would be that, since Kantian-type dignity has not actually been established, it gives us a way out of extreme scenarios such as runaway trolleys and Nazis at the door; scenarios in which a strict adherence to Kantian principles seems unreasonable.  This is no doubt full of holes, but I find it intriguing nonetheless.