Can I use conditional compilation for multiple extensions?

I’ve run into a bit of a weird problem.

There’s the classic extension Facing by Emily Short, which includes a useful bit of code. I’ve made my own variation on the whole thing, which (according to the I7 extension rules) is called Facing by Daniel Stelzer.

Now I’ve got a different extension I’ve written, which duplicates that bit of code (because the extension relies on that one bit, but doesn’t rely on the bulk of Facing, so I don’t want to make it a dependency). I’d like that bit to not be included twice (which is an error), so I’ve put it in a section marked “for use without Facing by Emily Short”.

Except…it’s, strictly speaking, for use without Facing by Emily Short or Facing by Daniel Stelzer, since they both include this same functionality.

Is there a way to represent this in I7?