He wont have servo operation if the radio fails which is his fear so there is no way to stop a glow engine if your radio fails for the reasons mentioned above.

In all my years of 72mhz and more recenlty 2.4 I've never had a glo issue so personally I wouilidn' worry about it. If you lose radio contact for reasons where the pre-set kill does not work... trust me your plane won't be flying away.. for very long anway ... probably 5 or 10 seconds before it hits terra firma.