Version 2018.00 adds the ability to export only the currently selected events to an .ics file. To select multiple events for export, click each event while holding the Ctrl key. A range of events can be selected by clicking the first event and holding the Shift key while clicking the last event. All events between the first and last events will be selected. This method of selecting multiple events works on both the calendar view (Day, Week, Month tabs) and the Event List. Selected events are indicated with a thick black border.
After selecting the events you'd like to export, click the "File -> Export -> Export Events" menu command. Select the option to export to an iCalendar (ics) file and click Next. Choose the "Selected events" option in the drop-down. The number of selected events will be shown. Click the Next button again to complete the export. Only the events that have been selected will be included in the .ics file.