I use the metal plates (galvanized I think) that are used in making trusses / rafters in building construction. Cut to fit the bottom of my boots, (more or less) and held in place there using old one-inch webbing straps "figure 8" up across meta-tarsals, around ankle, and then tied / clipped. They are cheap, work for a while, (until the sharp pointy bottoms get hammered flat). Light weight, cheap and easily replaced.
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