The problem I have with these ULR flights is the definition of such flights. EK, for instance, smartly defined ULRs as those flights over 16 hrs.
The bosses (who don't do any of those flights) insist they are legal. The flights could be legal, but are morally and phisiologically wrong.
Therefore, they get away with most of their long range flights, as far as crewing them is concerned.
We have flights to the Far East in which the crew is composed of one captain and two f/os. Most captains rarely rest properly on those flights; since they worry about being away from the cockpit manned by two "less qualified" colleagues.
In my view, any flight over eight hours flight time should have four pilots, period.
Obviously there are people who are good to fly again after a twenty-four resting period; most aren't. Fatigue has subtle symptoms which might not be recognized by most folks.