Thought I'd reply myself in case anyone else was interested Tried this out today at my local baby shop. They (awesomely) had the "connector 3" attached to their display BJCM. I showed the Freerider to my DS who promptly zoomed off on it around the store. Even though you can't "steer" with the handle, he seemed to get around well. I then attached it to the City Mini. Took me a minute to figure out the back wheel (it flips up underneath so it swivels) and took DS1 for a ride It was great! Because it is a scooter style board, it is mounted to the side so I can stand beside it to walk/push iykwim. It maneuvered well and because the board has its own handle DS could balance easily.

I ordered one on the spot when it arrives I'll take a photo!