Collected results of multiple characters/mules, 24 keys:
Out of 23 abjurations:
5 Escha abjurations
9 Lv. 99 (VW/Legion) abjurations
9 Lv. 75 (Sky/HNM/Ein) abjurations
Also got 1 non-abjuration item, a Hobgoblin pie (i.e. rolled an abjuration that character already had)
Also appears that specific slots are more common than others, corresponding to the Escha "difficulty" (hands&feet T1/most common, head&legs T2/less common, body T3 least common). I know it's a relatively small sample size, but pretty convincing numbers over 23 abjurations: I got 9 hands, 11 feet, 2 heads, 1 legs, and 0 bodies.
Specific drops (Escha abjurations in bold):
Supernal hands
Earthen feet
Supernal hands
Supernal feet
Transitory feet
Cyllenian hands
Transitory hands
Neptunal hands
Headean legs
Transitory feet
Lenitive feet
Transitory hands
Neptunal head
Earthen feet
Hadean hands
Cyllenian feet
Wyrmal feet
Hobgoblin pie
Aquarian feet
Shinryu feet
Arean hands
Transitory feet
Bushin hands
Neptunal hands