I was just thinking about those 474 dagger boards slipping.

I use 3/4 PVC pipe to protect the tensioning bungies and very heavy bungie cord and the boards still slip.

The down side of the heavy bungies is that they realy put some pressure on the tramp gommets.

I like your idea of the foam rollers. However last time I tried that the foam deteriorated pretty fast.

I'm half thinking that using some bike handlebar tape might add enough friction to those pesky dagger board bungie pipe keepers and bike tape is pretty tough and pretty inexpensive.

I've used that bike tape for years to soften and add some friction to the grips on my tiller hiking extensions.