I’m familiar with relays and have used them in the past to do the same thing. Do you have LED headlights? I heard it doesn’t work with the LED headlights.
Have you ever been to Alaska? Everybody has light bars. You can drive for hours in the dark without seeing another person and your life can depend on seeing a moose on the road.
Ford does surveys with their customers. If the lack of 4A in the XLT trim was losing Ford a bunch of sales or it was a huge feature XLT owners wanted I'm sure Ford would address the issue.