jere, the common knowledge around here (and I know that common knowledge can be wrong, and I can be wrong) is that short shifters do not harm the transmission. We've been through this argument before on our community and the short shifter harms transmission idea has been labeled a myth (I may or may not have been part of that. I don't remember.). Since you are bringing new knowledge in to our situation I feel it is your responsibility to provide evidence, or a theory, or something that backs up your claim.
I realize short shifter harms transmission is a concept touted and accepted in other car communities. If I were to bring up short shifters on another car forum that held that belief I fully accept that the burden of proof would be on me to show why I thought otherwise. In this situation, I believe it is your burden.
Also, I don't mean to "lay down the law" so to speak. I didn't have enough energy to explain why short shifters don't cause harm to transmissions at the time, nor do I know what harm you think they cause so I couldn't very well come up with a good rebuttal. I was leaving it up to the reader to decide who they'd like to believe I guess.