Mixed Results and Another Redesign
I was thinking in a similar way such as using curved (and smooth) channels as I have to lace up my hiking boots. Easy to lace up and they hold tight once tied off and, after over a year (five years for one set) I haven't had any damage to the laces, the guide hooks or the boots.
I think getting rid of the frame altogether is a fantastic idea. It could allow for a goalie to replace the netting mid-game if needed.
segmented, curved rope channels seems like it will have potential. A question though - why go with a partial cylinder on the sides? Wouldn't a full cylinder eliminate any chance of the rope slipping off the segment?
As always, enjoy following along as you develop this.