This may help. I put together this map showing where we have seen clear evidence of incursions of sea water inland and even over wash (yellow) and I've included the dates when the damage is known to have occurred. The purple areas indicate where there may have been sea water incursions in the past based upon the assumption that sea water "poisons" the ground for large trees such as Pisonia grandis (Buka) and Cordata subcordata (Kanawa).
I see clear evidence of sea water incursion on the west side of the atoll, which is what we would expect. Historically, heavy weather comes out of the west and northwest.
I see evidence of incursion along the north side of the lagoon shore and at the far end but not along the south side of the lagoon shore.
I see evidence of some incursion along the southern coastline, but no over wash except though the southern passage.
I see no evidence of incursion at either the Seven Site or the Aukeraime Shoe Site, so I think it's pretty hard to make the case that shoe parts migrated form one to the other.
Only coconuts migrate.
