On both web and the desktop client, I would love if you could (color) highlight a selected connector line.
In a complex flow diagram with hundreds of lines, following any one of them can be painful. It’s a little easier on the desktop client, but much harder on the web.
Ideally, instead of just a color highlight, changing the line thickness while it is the selected line (both platforms) would help the connection easy to visualize from the surrounding noise.