This sounds similar to the rules that the Americans apply to road cars and cages; therefore not a surprise.
Something to consider is that full cages (not common in Morgans, in fact, can't remember seeing one?
) can be quite dangerous if used on road. Having been designed for use with a helmet, the front (or rear section if they sit proud of the headrest) bars give no quarter in a RTA - and have been known kill on impact.
