The maxim that an attribute subsists in the subject qualified by it treats a genuine property as belonging to its bearer, not as an independently roaming object.
Saying divine will subsists in the divine essence is not a statement of bodily indwelling or spatial contact. It denies that the attribute belongs to another subject or is an originated quality without any subject.
Three accounts must therefore be distinguished: an eternal attribute subsisting in God, an originated attribute arising in God, and an originated will without a locus. These are different claims.