Thanks for the answer.
Unfortunately, the result is the same.
The call is made from the SDKDOMInstanceBase context.
I can get X, Y, width, height, but angle is always 0 and SetAngle doesn't seem to update anything.
Angle is working Editor side.
I have this line in the plugin.js file:
this._info.SetIsRotatable(true);
Maybe there is another setting to do elsewhere ?