The whole reference thing is a red heiring. Your question (as I understand it) pretty much boils down to "How do I split a list into pairs?" 
my @vals = map { @$_ } @{ $hash{$key} };

my @pairs;
while (@vals) {
   push @pairs, [ splice(@vals, 0, 2) ];
}

$hash{$key} = \@pairs;

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In reply to Re: Iterating through referenced arrays wihthin a hash by ikegami
in thread Iterating through referenced arrays wihthin a hash by AF_One

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