I am using OBS 28.0 and the obs-ptz-v0.15.4 plugin. The camera used is the PTZ-Mini, with a VISCA (Serial) connection, currently on USB COM3.
When starting OBS, the PTZ-Control does not work; the camera does not move. So, I need to close OBS, disable COM3 in the device manager, enable COM3 again, and then open OBS again. The camera control then works normally.
The problem is that I always have to do this every time I start OBS.
I had to create a script to do this automatically.
I upgraded to OBS 30.2.0 and PTZ Controls 0.18.0, but in this version, the control simply does not work, even after disabling and enabling COM3. In this version, the control stopped working, so I had to revert to OBS 28.0 and PTZ-Control 15.4.
The speed slider has been added back in another form. In the settings dialog there is a per-camera setting on the maximum Pan/Tilt, Zoom and Focus speeds. You can use that to limit the maximum speed that a camera will move. I'm still working on improving the UI, but I hope that will be a functional first step.