This is how I have supported my broad beans for the last few years once they’ve been planted out. They seem to do really well which is lovely, but also it’s a problem because the strings just don’t do a very good job of containing them.
This year (2024) I’m contemplating two changes. The first is to use canes tied to the stakes to provide a stronger support and stop the strings bending out over the paths as the plants flesh out. The second is to have more plants: it always seems to be that there are never enough beans of the ideal size at the same time, so more plants seems to be the solution. If there are too many they can just be blanched and frozen.