When using the Bepo pseudo-deadkeys (U+fdd7 etc), those end up as-is in the preedit text, which does not make sense, since preedit is meant to be Unicode, which I would interpret in this context to mean: a sequence of assigned Unicode codepoints.

What I've just done in GTK is to use the same center dot that we use to represent the compose key in preedit for U+fdd0 - U+fdd9 as well. Would be good if we could agree on that.