b2w2 eggs are the same as BW except the first egg uses a LCRNG seed from the save file.
there's always 6 calls to the twister first, and then inherited IVs overwrite them. not two.
so in that effect, the link you provided is wrong.
Also, no the encryption constant has no IV relation. Whatever that link noticed was just coincidence (with the plethora of provided bred PKX's, there's no way there's a relation between IVs and ec)