Does this type of simplification come from thinking like "the users", or am I just strange? Does this seem like a huge improvement to others? Anyone else felt "from the beginning" that Win32::API should be creating code refs, like that was the "natural" interface to provide?

I totally agree. A similar example for me is this from DBI:

  $rc = $sth->bind_col($col_num, \$col_variable);
  $rc = $sth->bind_columns(@list_of_refs_to_vars_to_bind);
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Ive never understood why that isnt:

  $rc = $sth->bind_col($col_num, $col_variable);
  $rc = $sth->bind_columns(@list_to_bind);
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my ($col_num)=@_;
my $col_variable=\$_[1];
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my @refs=map { \$_ } @_;
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