If you are between 72 and 24 hours then you as a Gold will indeed see a wider selection of seats than a Blue. This will consist of seats blocked because of a status passenger, also a Blue would typically only see a few options on a filling up aircraft. TS shows to them the other end of the telescope if you like.

For someone declared an assistance passenger then the rules are what they are, unless they have status. There is't supposed to be a dialogue about this.

If you are within 24 hours of travel then usually you can't do anything for another reason which is due to the fact that the seat is under FMU control. GGLs and Prems can sometimes get the agent to contact FMU but that's the exception rather than the rule.

So what you could do is use your TS block creatively - if the flight is not going to be full. However if the passenger is in the second cabin of CW upper deck then I wouldn't worry too much, the distance isn't great. If they are on main deck then you best see what you can do at the airport.

There are a lot of "if" statements here, as ever specific information gets specific advice.