Of course, Zaal Tsereteli's statistic method needs to be questioned,
I don’t claim I can or will ever be able to “decipher” (?) the Georgian notation (this is an impossible task given its imprecise, mnemonic character), but its strucural implications are in so many ways linked to the melodies passed in the classical Byzantine heirmologion / sticherarion that it would be strange to ignore it. This concerns both the minute details, such as occurrence of melismatic passages, or more global features like repetition of certain neumatic patterns, or even entire structures of the hymns as we know them from the middle Byzantine sources.
There is a huge corpus of Georgian heirmoi / automela that mimic the metrical structure of the Greek originals (at the expense of exactness of translation). Now from the Slavonic or Melchite sources we know a similar approach was used by other nations too to retain Greek melodies for translated texts. This is something the Georgian philologists were preaching already long ago, but it didn’t fall on a very fertile ground in Georgian musicology.