Both Collection.insert and Collection.update provide a named parameter to disable manipulators: "manipulate=False".
This option should also be available for the "find" method.

Going into implementation details: when "manipulate" is set to False the code for Cursor.next can be simplified to:

def next(self):
if not self.__empty:
if len(self.__data) or self._refresh():
return self.__data.pop(0)
raise StopIteration

Cursor._init_ could switch between both implementations of "next" according to the value of "manipulate".