So I used WSA as a reference and made the INPUT and OUTPUT the same for addHeader. It seems to have taken this time: 
my $ns = 'http://example.com/tns';
my $op = $wsdl->operation(...);

$op->addHeader(INPUT => "tns_token" => "{$ns}token");
$op->addHeader(OUTPUT => "tns_token" => "{$ns}token");

$call =  $op->compileClient(token => $sessionToken);

[download]
I got no complaints about token not being found. However, I still am not getting any header information in the SOAP envelope. Am I still missing something?

In reply to Re^4: Passing a session token using XML::Compile::WSDL by SeptamusNonovant
in thread Passing a session token using XML::Compile::WSDL by SeptamusNonovant

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