Two pilots (never mind the 3rd) can NOT get 3 hours rest on the MLE flight. No seat change allowed while in climb or descent. Flight time around 3:40 - do the maths. And that's not even going into the "no burnout" approved on these for the augmenter.
So normal limits (NOT Annex 1) apply. Which invariably puts you into discretion when your roster is published, up to 40 days before you operate.
That is not what discretion is for, it's for disruptions after sign on.
I was caught out the first time, I won't be doing it next time!!