This section applies only to Microsoft Windows platforms. See the LispWorks COM/Automation User Guide and Reference Manual for details.
Methods that are declared with the vararg attribute in the IDL or type library are now supported in a way that is compatible with the standard COM runtime. You should pass separate arguments in the an Automation call, but expect to receive them as an array in both COM and Automation method implementations.
LispWorks Release Notes and Installation Guide - 19 Oct 2017