In the 5.0 Beta stack, the usb_audio device class defines an audio_endpoint_data structure as part of the audio_device_struct, and the usb_hid class defines a hid_endpoint structure as part of the hid_device_struct.
Down inside them we find audio_endpoint_struct and hid_endpoint_struct definitions. Currently, part of these structs are guarded by conditional compilation on whether queuing is enabled for the device class.
Upon inspection of the device class driver code, it in fact appears that the entirety of the audio_endpoint_data and hid_endpoint_data are actually only used if queuing is enabled. To reduce memory usage, and code, for non-queuing apps, all of the *_endpoint_data stuff should probably be guarded on the queuing.