The following neatly illustrate the difference between the inherited long vowel and the result of consonant simplification.
πεδὰ πάνσας σπουδᾶς καὶ φιλοτιμίας Teos 7.7-8 (200 BCE) [cf. μετὰ
πάνσας σπουδᾶς καὶ φιλοτιμίας Teos 51.5-6 (200 BCE)].
μετὰ παίσας εὐκοσμίας and μετὰ παίσας εὐνοίας IG XII Suppl. 139.75 and 97 (before 167 BCE).
μετὰ πά̄σης σπουδῆς καὶ φιλοτιμίᾱς IG II³ 1170.15-16 (208/7 ΒCE).
'Aeolic' sometimes also shows <αι> for original <ᾱ>, but this must be hypercorrect. See Hooker (1977: 31-34) for a discussion of forms such as Βορίαις (Alc. 38.13), ἐπέραισε (Alc. 38a.8), ἐπτόαισε (Sapph. 22.14).
'Aeolic', or Mytilenian Lesbian, αἰμι- for ἡμι- (-θεος, -ονος is an unrelated phenomenon, but has epigraphic corroboration [gen.pl. of the adj. in lines 9 and 11]). See Buck, The Greek Dialects, section 17 and no. 25, and Schwyzer, GG I 185 Zusatz 3.
Sappho also has αἰμιτύβιον (119), a form not listed separately by LSJ s.v. ἡμιτύβιον.