Dear Sawad
in my opinion the storage recommendation of your supplier should be not only x month at -18 °C, but give different options at different temperatures for different times (we have 2 oer 3 option).
Regular fat is not as sensitive that you need frozen storage. Frozen storage is expensive and material is in a not "machinable".shape.
"Real" butter used in plant and in households has different storage recommendations, one is freezer condition (e.g. 4°C for x time).
We are a bakery and do not keep any fat frozen.
So, pls check with your supplier.
PS: In Germany and the EU it is not permitted to call a vegetable fat "butter".
Rgds
moskito