Thanks for the reply. On your suggestion I tried EnumAllObjects. As far as I can tell, this method seems to only enum objects created by Win32::OLE or latched onto by GetActiveObject. Running the documentation's example code supports this.

use Win32::OLE;
my $IE = Win32::OLE->GetActiveObject('InternetExplorer.Application');
print $Count = Win32::OLE->EnumAllObjects(sub {
            my $Object = shift;
            my $Class = Win32::OLE->QueryObjectType($Object);
            printf "# Object=%s Class=%s\n", $Object, $Class;
        });
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