Sorry for being OT, but here goes :
All the Super League teams ( 12 in 2007, 2008 & 2015 or 14 from 2009 to 2014 ) are involved in games over 2 days at 1 venue. In the years with 12 teams, it meant 2 triple headers & with 14, a triple header & a quadruple header.
There have been calls to give it a go in the NRL, but with 16 teams, it would be tough to arrange a convenient round & venue. I think it would be best supported if held at Suncorp Stadium with a double header ( Friday ) & then triple headers on Saturday & Sunday.
The other option would be double headers across the Easter weekend, but I don't know how the one ground would handle 8 games in such a short period of time.