Hi Hanzel,
I got curious and did some experimentation with this. I believe that my original suspicions were correct. I was able to retrieve a text location for an xref with the FP_TextRange property, but Frame would not let me add text in there, returning a FE_BadSelectionForOperation from F_ApiAddText(). So, I'll stick to my original workaround suggestion. Although it seems a bit convoluted, I don't think it would require too much code, maybe 20 lines or less.
Russ