I think the safest way to avoid problems with special characters is to use a single-quoted here-doc. There are no special characters in a single-quoted here doc:

print <<'EndOfText';
Hello! my name is "Bob". This is an old\new text.
EndOfText
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Now all you have to worry about is a line in the text matching the here-doc terminator. Here's a way to avoid that problem, in the script that creates the code:

$str = 'user input';
$str =~ s/^$/ /gm;   # add a space to each blank line
print <<"EndOfGeneratedCode";
print <<''; 
$str

EndOfGeneratedCode
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With a null terminator, a here-doc ends at the first empty line; the substitution replaces all the empty lines in the user's input with lines containing a single space.