Looks like there's not a whole lot of room there, but perhaps you could carefully extricate the old leash plug with a hole saw, and replace it, and then possibly double it up with a second leash plug rotated 90 degrees. Might have to peel back or cut another notch out of the traction pad to accomodate a second leash plug. I would suggest using a branded plug like Futures (particularly a narrow rectangular one--they seem far less likely to suffer from the rod failing) or FCS, rather than a random one from amazon/ebay/aliexpress. Then you use two seperate short paracord loops which your leash will attach to.
Usually leash plugs are taped and set under the fiberglass lamination for durability and then afterwards the opening is carefully cut open. Leash plugs can be retrofitted as well but I would recommend a fiberglass patch with epoxy extending at least an inch or two beyond the plug (or whatever fits). In your case the rod ripped out, rather than the plug, but its still a good idea. Big wave surfers use multiple leash plugs on their boards and super heavy duty leashes.