You are correct, Adaptive headlights mean you do not require high beam assist – so regardless of what the price list/brochure/web page says it will all be automatic the same as it is on the VW (only quicker – as I too discovered on the S-Max, VW’s system seems to be a tad slow).
I must admit, I didn’t think I’d be bothered about it when it came as part of the X pack for the S-Max, but its been so handy, especially as I drive in darkness so much of the time (daily 2 hour commute in darkness both ways from Oct-March).
In life, it's not who you know that's important, it's how your wife found out.