data is casted with native PHP cast feature in Laravel code: (object) $result and (array) $result.

Note that we could leverage the cast_object object handler in extension classes to facilitate converting a PackedArray into an array.

https://github.com/mongodb/laravel-mongodb/pull/3107#issuecomment-2309658318

This would be useful for MongoDB\BSON\PackedArray and MongoDB\BSON\Document.

But, I'm not sure we can implement it for PHPLIB classes 
MongoDB\Model\BSONDocument and MongoDB\Model\BSONArray