Thanks so much for the feedback BTW. This sort of detailed bug reporting is hard to come by, and makes my job of fixing stuff infinitely easier ??
This particular plugin is a little hard for me to bug fix, since I’m not using it on any live sites any longer (I was back when I first launched it, but not anymore).
Hopefully if we can get all the bugs ironed out of it now, it will be plain sailing for the next few years though. The Unique Headers plugin needed a bit of a shakeup as I made some errors in the earlier builds. But I never transferred the changes over to this addon plugin. But I think the Unique Headers code base should be quite stable from now on, which should make this addon plugin also stable. So I’m not expecting any major issues going forward (other than any other bugs you may find in this existing implementation of it).