Enable subclassing of EmbeddedDocumentList

While trying to achieve a more native/OOP like use of the models in my code, I encountered the following issue:
I have the following structure:

• class P(Document)
• class M(EmbeddedDocument)

P contains a list of Ms, hence in the definition of P I have:
ms = EmbeddedDocumentListField(M)
The problem is that I want to achieve the following usage:

p = P()
p.ms.my_creation_func()

To enable that, I need the object that returns from p.ms to have my_creation_func. Since ms is defined with a descriptor, that receives only the class that inherits from EmbeddedDocument, I have no way of achieving that properly.

The solution I have for now, is to subclass the whole triplet (EmbeddedDocument, EmbeddedDocumentList, EmbeddedDocumentListField), and allow the subclass of EmbeddedDocumentListField to accept the class of the list it wraps as a constructor parameter.
To wrap it up, I need to override the __get__ function of the EmbeddedDocumentListField's subclass. by combining all of the __get__ functions that appear throughout the inheritance tree, and modify them to work with the list class I provided as a parameter, instead of working with EmbeddedDocumentList.

A good solution would allow the EmbeddedDocumentListField c'tor to accept the list class as a parameter, put it in some field, and the __get__ functions in the super classes to work with that field.

If there's any other solution, which I can apply locally, I'd be glad to know.

Start by tracing EmbeddedDocumentListField and its get implementations, along with EmbeddedDocumentList and EmbeddedDocument. Reproduce the P, M, and ms = EmbeddedDocumentListField(M) example, then determine whether accepting a custom list class preserves the existing descriptor behavior. Done means a subclass can expose its own method through p.ms without requiring a separate reimplementation of the descriptor hierarchy.