It's worked for me twice (Albany let me schedule around my Columbia interview, and Jefferson let me schedule around my MCPH interview), not worked multiple times that didn't result in speedy rejection (Rochester couldn't let me know in time, but later offered me an interview -- the invite came while I was in NY for the Columbia/Albany interviews. Other schools that said no I haven't heard anything more from), and speeded up my rejection at JHU (I have the distinction of being the first SDNer to be rejected by them!). So I don't think asking them to allow you to coordinate interviews is necessarily the kiss of death. I think that in some cases it just might speed up your notification of a rejection, not cause it. In the vast majority of cases it has no effect. Occasionally you'll find a school that will bend over backwards, for whatever reason, to help you.