Although it is good to have the LDG tuner work from a rig with a tune command, but the LDG tuners can operate in automatic where when they see RF and SWR above 1.5:1 they automatically tune.? So only the RF cables need to be connected for them to work.
I prefer the command cable be connected, but if that is not an option just letting the tuner tune on it's own will work.? Just put the rig in RTTY or other CW cont? xmt mode and let the tuner do it's thing.