  In a previous article, we constructed an invariant Z for null-homologous
knots in rational homology spheres, from equivariant intersections in
configuration spaces. Here we present an equivalent definition of Z in terms of
configuration space integrals, we prove that Z is multiplicative under
connected sum, and we prove null Lagrangian-preserving surgery formulae for Z.
Our formulae generalize similar formulae that are satisfied by the Kricker
rational lift of the Kontsevich integral for null Borromean surgeries. They
imply that Z is universal with respect to a natural filtration. According to
results of Garoufalidis and Rozansky, they therefore imply that Z is equivalent
to the Kricker lift of the Kontsevich integral for null-homologous knots with
trivial Alexander polynomial in integral homology spheres.
