Hey Keith,
I spoke with one of our developers and there unfortunately isn’t a hook that we have built into the plugin that would fire for imported events.
However, there is an approach that you could take that would allow you to hook into the default WordPress save post function and conditionally run your code if it originated from an import. This would look something like:
add_action( 'wp_ajax_tribe_events_ical-importer_run_saved_import_query', function() {
add_action( 'save_post_tribe_events', function( $event ) {
// Code here should execute when an event is saved during the iCal import process
}
}, 5 );
Let me know if this helps.
Thanks!