JSON's encode() function would create a UTF8 text string out of the shared hash, so I just decoded() it back into an (unshared) HREF, and then I just stored that.

my $encoded = JSON::XS->new->utf8->encode( $HREF );
my $decoded = JSON::XS->new->utf8->decode( $encoded );
store $decoded, $filename1;
[download]

or I could just slap it all into one statement:

store(JSON::XS->new->utf8->decode(
      JSON::XS->new->utf8->encode( $HREF ) ),
      $filename1);
[download]

and all is well in the universe again!