You are correct, the leftmost map() is redundant.

The code seems overly complicated however, the following has the same effect:

    my %tmp = %$test;
    delete $tmp{$first};
    my @list3 = ([$first, ''], map {[$_, $_]} sort keys %tmp);
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Also, the hashref could really just be a plain hash, unless you need to use it elsewhere.

--
John.