With the release of version 1.12, it is now possible to install and have TwinCAT 3 HMI running on a Windows CE control system, for instance a CX9020.
Mattias Nilsson, one of my colleagues, made a wonderful article how to install the HMI server and how to config it.
The post is available on LinkedIn, but as I see it can be read without any account.
Article: TwinCAT 3 HMI on Windows CE
Author: Mattias Nilsson
Publicated: 26th Augist 2020