Cheap way to stabilize your trailer
Run-out jacks are an interesting idea that that could provide some improvement over scissor jacks and would most useful in reducing potential tip-over under very high wind conditions. However the supports as pictured would seem to do little to reduce sideways motion, fore-and-aft movement, horizontal rotation, and vertical motion resulting from trailer frame flexibility and its suspension components (springs and tires). All of these other kinds of trailer instabilities are very annoying to a lot of folks and can only be significantly reduced by placing additional jacks near the tires to take some of the load off the suspension system, and also adding diagonal horizontal and longitudinal bracing from the frame to the ground, as is accomplished by some of the commercially available stabilizing systems. The good news is for less than a $100 a do-it-yourselfer can buy a set of four Walmart jacks, some thinwall round fence tubing, frame clamps, nuts and bolts, a length of 2X treated wood for pads, and build himself a simple diagonal trailer stabilizing system that is rock-solid (and can be diassembled and reused as needed).