"multipart/form-data" Request Body Schema Inconsistency With Inline Definition Versus Reference

[alex-leroux]

If I have the following definition for the request body of an operation:

  requestBody:
    description: Contact data
    content:
      multipart/form-data:
        schema:
          type: object
          properties:
            emailAddress:
              type: string
            firstName:
              type: string
            lastName:
              type: string

... then the OperationModelBase will contain a parameter for each of the properties.

However, if I have the following (functionally equivalent) definition for the request body:

  requestBody:
    description: Contact data
    content:
      multipart/form-data:
        schema:
          $ref: '#/components/schemas/Contact'

... then the OperationModelBase will contain a body parameter, of a type which has a property for each of the properties.

I am using versions 13.11.3.

Is it correct that these two scenarios are treated differently?
(they behave differently because line 342 in OperationModelBase uses .Schema rather than .ActualSchema.

May I also please ask why "multipart/form-data" is treated this way? As opposed to other form request content types, like "application/x-www-form-urlencoded" or "multipart/mixed"?