Yes; this is an example where a very useful codepoint is unlikely to be endorsed by unicode. We could use two shaddas, one phonotactic and one lexical. I think there might even be a third case but I can't think of it at the moment.
By using an idghaam codepoint they could be easily distinguished.
I feel compelled to say (to everyone here, not just you Gregg, and not particularly in terms of this thread) that the arabs already have conducted an immensely rich analysis of the arabic language and its morphology, phonetics etc in respect of the quran. To abandon that (probably out of ignorance rather than deliberately) would be an immense mistake.
We should stick to the time-honoured names that all good arab and muslim scholars are already familiar with. To try and come up with a new lexicon based on western phonetic and morphological terms is a big mistake.