TRV
These flights are not operated to Variation 1. case in point the rest required before the variation (Nights rest) which is definitely not the case on the 330 fleet to TRV. Planned duty 11 hours. Max duty 10 hrs 15 min. (extension from variation 1 is only 30 min). The only way to extend the duty is with augmentation 1hr if the operating pilots receive 3 hrs rest (not consecutive) which means a change in seats during climb and descent ( above FL 200) doable on paper but not in reality.
Discretion is a quagmire! can you exercise it if you are planned to exceed duty?. I would think not.