The Dôme des Glaciers is a high moutain site with easy takeoff : snow, long slight slope. Orientation S-SW.
There are several possibilities to takeoff between the col du Moyen-Âge and the Dôme des Glaciers you might use and chose depending on the weather, wind, snow conditions,…
Confortable landing on grassy (almost) flat areas in the vallée des Glaciers between les Lanchettes ans les Chapieux.
Important note : be careful of the wind wich might be very different between takeoff and landing due to the col de la Seigne.
And it plays in speed!
Some info here with the list of various reports .