I guess I could lift the decking, though the thought of it gives me the dry itch.
Could you not remove the trim and fascia (on the right of photo), unclip the small deck board and remove, then unscrew the clips to the adjacent boards and slide them along till you've got a gap to feed the conduit from?
Could you not remove the trim and fascia (on the right of photo), unclip the small deck board and remove, then unscrew the clips to the adjacent boards and slide them along till you've got a gap to feed the conduit from?