I have a CLH trailer for my Bayraider with extending arms at the back which hold (or held) the lighting board. This tended to shake loose and is low enough to scrape on the ground when starting to ascend a steep slope (such as outside my garage). In addition, because the trailer lights are so low, drivers of a certain nationality that believe in driving 6 inches (15.24 cm) behind in order to, er, benefit from your slipstream (think revenge of the frigate) are probably unable to see them as your transom fills the whole of their vision.
On my way back today after travelling a total of 2,500 miles, I had my only equipment failure in a month of hard sailing and trailing. Yep, one extending arm fell off completely and the lighting board was unceremoniously dragged end on along the M6.
My conclusion is that the CLH lighting board bracket system is nbg. I am going to use my swim ladder winglets on the top of the rudder fabrication (see Going for a Swim thread) to attach a robust lighting board bracket. This will be much higher and thus more visible to tailgaters, will not get in the way on slopes, will not get wet when I forget to demount it, will not vibrate so much that it pops the bulbs and will not fall off under most circumstances. I will post a picture when it is done.