Oh we’ve taken off in that direction too. JetBlue to NY but that does make logistical sense (to me at least ) since you are headed in the right direction
They did it everytime for two weeks in January. If the winds are neutral (calm) to favorable (headwind) it is their choice. Probably saves fuel as you get a normal climbout and a right 180ish turn enroute to Paris. Taking off towards the mountain requires an immediate climbing right turn and then either a left S turn to Paris or 3-3.5 more right turns (270ish) to get on course to Paris.
I guess. I found this interesting.
Runway procedures http://www.uvairlines.com/admin/resources/TNCM.pdf] Runway 10 takeoff procedures. Seems the Ai Frances usual runway 28 (these days ) burns more fuel. Ultimately thought, it’s the pilots call
Just interesting.
