आगमे ब्राह्मे विश्वासटिप्पन्यः

reject his (KuppusvAmi shAstri) identification of dramidacharya with tirumazhisai for obvious reasons.

If it was so, we would be seeing yamuna, ramanuja, desika etc mentioning abt this identity somewhere - we see no such reference. no hagiography mentions abt such Sanskrit works either. Otoh, we hear how he avoided reciting any Vedic phrase in keeping with his varna dharma. And none of the reasons given by sastri are really strong.

Upavarsha - bodhayana identity is accepted. Desikan himself says so. (Yes but according to van Buitenen, Desika is not asserting this himself but merely quotes Sabaraswamin’s quotation in his bhashya on PMS 1.1.5 identifying Bodhayana with Upavarsha.)