What does this syntax do:

open STDERR, '>&', \*STDOUT'

because this simpler syntax seems to work:

     1  use strict;
     2  use warnings;
     3  use 5.010;
     4
     5  open my $SAVE_STDOUT, '>&', 'STDOUT';  #<--quoted bareword
     6  open STDOUT, '>', 'data1.txt';
     7  say 'hello world';
     8
     9  open my $SAVE_STDERR, '>&', 'STDERR';  #<--quoted bareword
    10  open STDERR, '>', 'errors.txt';
    11  warn "my warning message";
    12
    13  open STDOUT, '>&', $SAVE_STDOUT;
    14  open STDERR, '>&', $SAVE_STDERR;
    15  say 'goodbye';
    16  warn 'my warning message #2';

--output:--
goodbye
my warning message #2 at 2perl.pl line 16.

$cat data1.txt
hello world

$cat errors.txt
my warning message at 2perl.pl line 11.
[download]

Then go for it. Some functions have funky parsing rules that accept barewords. Some functions accept the names of file handles. This is has does both.

However, I disagree that passing a file handle* to a function that expects a file handle is somehow more complex than passing the name of the file handle you want to pass. (I should have used *STDOUT, though. There was no need to take a reference, although references to glob work a bit more often than just globs.)

By the way, the real name for "quoted bareword" is "quoted string literal" or (laxly) "quoted string".

* — Well, technically, the file handle is obtained by dereferencing *STDOUT{IO}, but *STDOUT is one step closer than 'STDOUT'.