I think you'll find that these will bend as well without some serious lengthwise bracing. The waffle boards actually can be use for bridging, and have been used that way for years. Very popular for that over in England. They're also lightweight and, in this case, pretty cheap.
About 15 years ago, I built a set of traction aids out of galvanized steel grating that was used for industrial steps, with the tread cut and bent into a diamond tread. They were formed so that they had structural integrity, and I added a frame of 1" square tube. The whole thing could be bolted together and configured into a camp table, with the 1" stiffeners becoming legs. They worked pretty well as a traction aid every time I used them, but they were heavy and kind of cumbersome to carry around. They now sit in my garage under my gear oil drums and pans.
Even a few years ago there weren't many options for sand ladders or bridging aids other than fabricating your own or spending $200-$400 on ones from Land Rover patrs houses. Instead, I put my money into winches that saw much more use and were much more effective. In my trail Jeep, there are few instances where I would need a bridging ladder. I have Swampers and ARBs and a winch. With my less-built Rover, I may opt for some of these bridging ladders, since they will likely fit in with my "less traction and more extraction" plan.