Implement interesting firmware workaround for x05 models to force lap

Implement interesting firmware workaround for x05 models to force lap
closure  so that stored tracks can be retrieved.

Note that this forces the widening of the command array to two bytes -
it's always technically _been_ two byts, but we've never had a command
# > 127 before. This does have the potential to expose naughtiness if
we've missed any endian swaps...