An Interfolio for References Downside

I've been using Interfolio to manage references during the job search. I've not worried particularly about whether committees will react badly to it; as far as I'm concerned they can suck up that they don't get letters tailored to them specifically from every person involved in the process since they ask for so much information at the start of the process in my field.

The decision to use it was based around the fact that getting reference letters from afar, like managing a dissertation from far off, is like herding cats. It was easier to me to set one deadline with everyone, to ask each reference to highlight particular things, and to have some bit of a backup. Part of why it's necessary is that I've taught at two very different types of schools in addition to the grad school related issues. So I want references that will highlight that I thrived in my One Year Visiting at a Research I as well as references that can talk about how I've been good for the SLAC that I'm currently at. I want to make sure someone is talking about how useful my research is and how good my teaching is. I need someone to talk about both undergraduate work and my experiences teaching graduate students.

But even with Interfolio, it's still cats being herded. Part of my backup was to have an extra reference letter available. One from my dissertation adviser (covering research), one from my current department chair, one from my current dean, and one from my division chair at the one year where, among other things, I gained experience with graduate students.

Naturally, only three of the four letters came in on time for the 15 applications I sent out (please note, more than a month and a half was given before the first deadline for the reference letters). The fourth one came in today, and I'm left with the question of whether that fourth letter is worth sending out, even to a limited number of places, at the $5 per mailing cost.