The Sanaa Palimpsest
english.alaraby.co.uk
english.alaraby.co.uk
It's surprising the article does not mention this. The palimpsest likely shows one of the variants that did not survive the purge.
The closest thing to a variant would be one of the ten "readings" or https://en.wikipedia.org/wiki/Qira%CA%BCat
Much research remains before scholars will be able to definitively answer these questions. Including a thorough, technologically sophisticated analysis of this special manuscript, half of which is still stored by the Library of Religious Endowments at the Great Mosque of Sanaa and has not been yet properly photographed.
Interesting that we still find versions of old texts that show a richness in variants.