Since the carb is enclosed in the cowl, there shouldn't be much, if any, of a siphoning problem. Starting the engine without being able to choke it is another story. If you really don't want the hole for the choke actuator, use a spare channel and linkage to actuate the choke via servo. However, IMO, the hole and choke actuating rod will not be detrimental to your plane's appearance.

Dr.1