> "You can't really use them for hauling heavy loads, so forget bicycle touring or pulling a little trailer for kids or other things"

Eh?

https://www.youtube.com/watch?v=XzRqKP0XmhQ - Brompton with Burley Travoy trailer while the guy moves house.

https://www.youtube.com/watch?v=ocMRuUBUFrU - Bromtpon with Cyclone trailer while grocery shopping.

https://www.youtube.com/watch?v=tvBA1K8oFmQ - Brompton with child trailer.

https://www.youtube.com/watch?v=hOH3wEB0pS8 - with different child trailer.

https://www.youtube.com/watch?v=waW1wq07JsA - Brompton with child seat adapter in front of the rider.

https://www.youtube.com/watch?v=aV60S7ma4d4 - Brompton with child seat on the back.