Findings on Parents' Island Gate

been trying to create a Parents' Island and notice this:

https://i.imgur.com/6J5NGt5.png
It can place on all "road" and "pavement" features.

https://i.imgur.com/jKCNvgo.png
It can place on a bridge as well.


https://i.imgur.com/4FQjR3X.png
Only "pavement" (Pavement & Dirt) features can be placed on the two ends of the gate, but "road" (Road, Dirt Road, Ice Tile, Krustyland Path, River) cant.
couldnt test on Cobblestone Road because I havent unlock it.


Hope this might help.