I looked into Sony\'s developer website (3 March 2018) and while the design is changed, the contents seem to lag behind.
https://developer.sony.com/develop/cameras
Since feb 2020 Sony has provided a new wirelessly remote SDK. The Camera Remote SDK is a flexible API that builds on commonly-used protocols such as HTTP and JSON. And you can develop apps for any operating system, such as Android, iOS or Microsoft Windows.
See Api Information for supported devices (notification 2020-09-15). Only ILCE-7C, ILCE-7SM3, ILCE-7RM4, ILCE-9M2 are supported now.