yes that is mostly correct apart from the one off dispo that the caa have given easy to have the two different certifications which normally wouldn't be allowed under eu ops.
our present fearless leader AH told us at sep day that easy was not the first operator to have 150 seat 319s and that this was the basis for their argument to be able to change them back. He also said that when it suited economically they would change them back to 156. I was sitting in front of him when he said it.
having said all that he does speak with forked tongue and as a rule i dont believe much he says but.
the point is that where a buck is involved rules can be manipulated by operators like the orange one and the regulators just fall into line.