I tried Grammarian Pro 2 some years ago, but found that I was unable to type diacritics such as macrons when using Grammarian’s input method. I contacted the developer at the time, but he didn’t have a solution, and when I tried Grammarian Pro 3 soon after it was released, it still hadn’t been fixed. I have wondered whether it might be because Grammarian isn’t Unicode-compliant, but at any rate it makes Grammarian unusable for me.