The supported API grid indicated that the a5000 should have post view image size functions, but the APIs are not available when I call getAvailableAPIList. I am careful to initialize with startRecMode, and am sure that the camera function is set to "remote shooting." Other expected APIs are there such as actTakePicture, but not getPostviewImageSize, setPostviewImageSize, getSupportedPostviewImageSize, or getAvailablePostviewImageSize.
I have verified that my camera has the latest firmware.