<That is, niggahiita is phonetically a nasalized extension of the vowel
which precedes it>
This may explain why Buddhapiya's "etymological" explanation states that
ni-ggahiita is obtained (gayhati) on the basis of (ni-ssaaya) a preceding
short vowel.
<The absence of concern with phonetic detail is noteworthy in the Pali
tradition. Every grammar treats sandhi, but there are no phonetic treatises
(to my knowledge)>
The author of the Vinaya commentary addresses instances of
mispronunciations. The treatment is phonetically interesting in that it
sheds light on 5. c. AD Sinhalese perception of correctly pronounced Pali
text. The grammarians' description of sandhi is interesting as they noticed
the use of glides, but the treatment is at best rudimentary. This feature of
the language is in need of a thorough treatment. Strangely there are no Pali
treatises comparable to the Sanskrit phonetic treatises that address the use
of glides.
<Perhaps it was felt that the Sanskrit phoneticians had exhausted the
subject>
I believe you are right.
Regards,
Ole Pind