Now, what I find really nifty is the way that in tengwar these sorts
of relationships between sounds are what the writing system is based
on - the symbols for voiced/unvoiced pairs are variants of each other,
only different in one feature, for sounds where air goes from not
going through your mouth to going through your mouth are again
different in only one feature from the associated sounds where air is
always flowing or where no air is flowing (nasals). I've actually been
using them to help me get pronunciation. The theory is slightly
different, though, so it has some symbols that aren't used.
It seems to me potentially worthwhile to have a similarly logical
writing system as an option, perhaps a bit more fitted to the lojban
phoneme set and structure.
-Jonathan