How to create dummy devices

How can I create dummy devices that act like a light or shutter device? I just want virtual devices that can be controlled like a real one, 0%-100%, on/off, up/down.
I know that I can do this with iobroker data points, but this seems to be unreliable, so I want to test an alternative way, especially when I add f.e. 15 shutters in a group “All shutters” in Alexa, and say “All shutters on” (since “up” or “down” is rejected), the blockly routine gets overloaded somehow, but a single shutter request works well for all shutters. Thanks in advance.

The API allows you to create a CLIP sensor (switch and other types) but I have not attempted this and nor am I certain that they are displayed in Phoscon to enable automation.

https://dresden-elektronik.github.io/deconz-rest-doc/endpoints/sensors/#clip-sensor-types-and-states

The new Phoscon Desktop is under development and this will expand some capabilities to assign window devices to room and groups however currently this isn’t in the Phoscon beta dated 7 Mar 2025. It maybe worth asking a question in that thread on what and when that is expected.

https://deconz.dresden-elektronik.de/phoscon_app/phoscon_app_dashboard_2025-03-07.zip