Short primitive [e] was generally preserved in both Danian dialects, though it could in some circumstances develop into a diphthong through vowel breaking, such as before consonant clusters beginning with [l], [r] or after an initial [sk]. It is also possibly that this vowel was modified by Danian i-mutation (into [i]?), but there are no attested examples.
There are, however, examples of primitive [a] becoming [e] via i-mutation, such as Gochressiel from hrassa “precipice” (Ety/KHARÁS). There are also other examples of [a] developing into [e] in the words spenna and sc(i)ella, but the exact mechanism is unclear.
This is one note indicating that “in East Danian & Taliska e became normally i” (PE19/26), but this change probably refers to an earlier conception when both East Danian and Taliska said to resemble Gothic (PE19/22 note #55). After East Danian was reassigned to the “Old Norse” type, this change probably only referred to Taliska.