Based on my experience on my MacBook Air the answer is No, it won't let you e-file. I went through this earlier today, and got all the way through the process, clicked on e-file for both federal and state returns, and received a message something like "we've encountered a problem. you can try to e-file again or print your return and mail it" (not a direct quote). Fortunately, I also have a desktop PC and I could do the suggested alternative of creating an attachment folder on the c: drive and including a copy of the Form 1116 Schedule B, named as suggested, and that worked. Someone else suggested doing this on a Mac on the main drive but I haven't tried that.
