BTW, I see that the 4L versions are listed on the Kegland site. I am curious when these will make it to the US. Maybe @KegLand can let us know!
https://www.kegland.com.au/4l-oxebar-mono-polymer-pco38-keg-with-cap-and-handle.html
https://www.kegland.com.au/4l-oxebar-mono-polymer-pco38-keg-with-cap-and-handle.html