They should give up on the barge idea and simply land it on a remote landmass,
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Landing on land is easier, but that still would have failed in this case because a landing leg didn’t lock. Barge landings are necessary because not all missions will have enough fuel to return the launchpad.
True, unless the first stage had enough flight surface to make the glide back. Maybe the extendable legs could become fixed fins with perhaps fixed or extendable canards near the top of the first stage body for additional lift and control?