After some code cleanup (still there is some more to be done) I have committed some changes for non-linear constraints handling. If your constraints are split, for example
p.c = [c1, c2, c3],
p.h = [h1, h2]
some solvers can take benefits (ralg for c and h, ALGENCAN for c; others available for now in OO cannot).
They will take less evaluations for these non-linear constraints.