Ellie,

I think the Durians are frozen mainly if they are out of the main season.
So it's no a good idea to request for durians the whole year. You will get
what you have asked for but at the expense of quality.
Prices may play a role too since frozen durian should be cheaper than fresh
one (easier transportation.) However in the main season it should always be
possible to get fresh one.
Little accidents in hard winter may happen... no cooked fooder will watch for
this.

Kind regards,

Stefan