There is no current curved LED tool unfortunately. I build them as individual screens but you then need to build content for each section of the screen. As i visualise a lot of these my workflow is generally to draw a Regular Polygon with sides the length of each panel and the number of sides to reflect the angle between each panel (ie 360/x). This gives me the required diameter etc. I then use either the LED screen to create a 1 panel wide by x high LED screen, line this up with the polygon and then use duplicate array to create a circular duplication. If i need to add screen content I just create an extrude the same shape as the face of the entire screen and apply texture to this.
Hoping this gets built into the LED screen tool, I'm sure it's been requested