one good thing with this is that because the man on the mark is fixed it will make it easier for everyone, but especially the umpire, to see the actual mark and therefore the kicker's legal "line"
this will make it easier to spot when a player goes off-line and therefore to call play-on
if the umpires are going to be strict with man-on-mark then they need to be just as strict with kicker going off their line, which is something we see all too frequently, especially around the boundaries
only time will tell how well umpires adjudicate both these situations