I'm trying a plastic welder on my worst panel. But I have FantaSea panels and they are very different from the rollable ones. They are 2'x4' and you walk on them.

The welder looks like an electronics soldering iron on steroids. It has variable control and comes with ALL kinds of plastic welding materials, including a heat-activated adhesive that's about as good as welding and doesn't actually melt the plastic on the target.

I got from some tool supply house called, I think, Arizona Tools (?). Seems to work pretty well.