The "packed" accountability constraint polynomials (a4 and a7 in https://hackmd.io/N1TNor2lQsyBz2c2aX9nWw) are both degree <= 2(n-1) polynomials, where n is the domain size. Still, to compute them the evaluations of the register polynomials c and acc are amplified from n to 4n points, as for the "basic" registers where the highest constraint polynomial degree is < 4n, while 2x amplification would be enough.
The ideal solution would be to somehow encapsulate that stuff within arkworks' polynomial arithmetic.
The "packed" accountability constraint polynomials (a4 and a7 in https://hackmd.io/N1TNor2lQsyBz2c2aX9nWw) are both degree <= 2(n-1) polynomials, where n is the domain size. Still, to compute them the evaluations of the register polynomials c and acc are amplified from n to 4n points, as for the "basic" registers where the highest constraint polynomial degree is < 4n, while 2x amplification would be enough.
The ideal solution would be to somehow encapsulate that stuff within arkworks' polynomial arithmetic.