Thanks for hosting barman :] fun
It's definitely a 'new' concept to introduce to Elite, but none of my games even had any reason to knock, even in my last one vs Barman, he did a knock, but it probably wasn't even necessary.
4 worms in Elite is likely a big factor why, whereas in Intermediate when there's so many worms (eight), you have more reason to try knocking. Overall, my impression is I'm still not convinced Rope Knocking really needs to be added to Elite just for the sake of changing something. Sure this was a small sample size with Bo1 games in an 8 player tournament, but I'd still wager that Rope Knocking when allowed would probably happen way less than you might think, and not even be a factor in most all games.