From the Metzler site:
According to the specific regulations of different country governments, a general recommendation regarding tire repair cannot be given. For your country, please refer to your distributor. In case a repair is permitted, METZELER is only recommending the repair of small punctures restricted to the tread area using a mushroom head type plug. The repair of a punctured tubeless tire by means of fitting a tube is not permitted .
It goes on to mention specifics on failures and that it is okay to use a tubeless tire on a tube rim, but, not vice versa. This may be why Honda North wouldn't do it.
