With Ensemble models, you can choose a specific member in the ensemble. For non-premium members, you can only use Control and master forecast. Premium users can …

In Windy there is NO Ensemble models, so why do you say “you can” ? At least I would understand that you say “you could”

you can choose a specific member in the ensemble

There is no point in choosing a member of the ensemble.
The only purpose of ensemble models is to provide a forecast probability.
It is clearly explained here.