I prefer to pronounce the i-component in ῃ ᾳ ῳ . Pronouncing them the same as η α ω risks encouraging spelling errors. That is shown down the centuries in India, where Sanskrit is the classical language: the old custom there was to pronounce “ŗ” (r with a dot below, anciently r as a vowel) as “ri”, and as a result in India there are many Sanskrit inscriptions with spelling errors between “ŗ” and “ri”.
The examples that Erasmus (who was Dutch) used for his idea of the Ancient Greek pronunciations of ει and ου, were the Dutch word “ei” = ‘egg’, and the vowel in the Dutch words “oud” = ‘old’ and “koud” = ‘cold’. Which he somewhat unclearly described as “ut Batavi dicunt ovum” and “ut dicimus senex et frigidus”, or similar. (I can agree, because I taught myself Dutch for two holidays motorcycling round Holland.)