GT compression
See https://github.com/ConsenSys/gnark-crypto/blob/master/ecc/bls12-381/internal/fptower/e12.go#L756 (and this ref https://github.com/ConsenSys/gnark-crypto/blob/master/ecc/bls12-381/internal/fptower/e12.go#L790)
Can be important for aplonk.
Edited by Danny Willems