Yes, everything you say I am aware of. I am not against the current Byzantine notation. Foremost, I am not an expert in that notation, nor music, and I have to learn a lot, and I want to learn a lot.
However, I am more than sure that all Byzantine (church)music is possible to notate, with a powerful yet simple notation of the 'western' type, so meticulously even of the most complex type.
For the notation is not a fixed thing, so even the old Byzantine notation is not in use today, yet the music from 7 century was preserved.
What I am most concerned about is westernisation of the Orthodox Church music because of just - notation. If, I am saying here if, the music notation was adopted to easily represent any of the melismas, microtones, ornaments, irregular meter and so on (adopted = widely recognised and standardised), than we would perhaps not have a "4-part-protestant-like-bach-choral" influence on Bortnansky, Gretchaninov, Mokranjac, Tchaikovsky etc. Just having hermetically closed the Byzantine Music notation, the rest of Orthodox music (everything non-hellenic*) is left open to the influence of, just that, the Protestant and Roman Catholic tradition. For what is the most bizarre than to hear during the Orthodox Church service the full authentic cadence in 4-part strict voice-leading. Just my opinion.
*) there are for sure other notational types such as Georgian old, znamenny etc. yet not as widely recognised as the Byzantine, but as much hermetical.