Although quite many machzorim omit it, but there are lengthy selichot composed for all services on Yom Kippur. Is it only an Ashkenazi custom?
ב"נ I will post here the selichot of different communities that I find.
Angelo Piattelli posted on his site the full set of Italian machzorim he edited with R. Hillel Sermoneta based on the Roman tradition that is in use in Jerusalem. In the Yom Kippur machzor one may find all the selichot, in particular (page numbers according to PDF):
- Maariv: p. 93
- Shacharit: p. 247
- Minchah: p. 476
- Neilah: p. 518
The Spanish and Portuguese communities had a machzor from 1821 translated by Lazzaro Emanuele Ottolenghi.
Aram Tzova rite
The Aleppo community from Syria had a very special set of selichot for Yom Kippur that survives in the Aram Tzova Machzor from 1527.