Demand loading of an ObjectARX application on AutoCAD startup can be specified by using 0x02 (or you can perform an OR 0x02 with another legitimate value) with the LOADCTRLS value in the system registry, as shown here.
\\HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R25.0\ ACAD-8101:409\ Applications\PolyCAD\ LOADCTRLS:REG_DWORD:0x02