I haven't seen that strap; looks like an interesting design. Yet, like most straps, once any portion of the weave is frayed, the strap because exponentially weaker.
Having towed/been towed too many of my fair share of motorcycles, over flat tarmac to knarly terrain, regardless of strap, IMO there is only one safe way to tow another moto.
I always wrap the strap around the towed bike's footpeg with the minimum number of wraps to prevent slippage. If things get sketchy, the towed rider only needs to lift his foot for the strap to slip off the footpeg and the two bikes are separated. Of course, this method can present issues if you have to duck waddle the towed bike.
If you use aggressive style footpegs simply place something over the aggressive teeth. I keep cut up sections of a 1 gallon paint can stirring stick wrapped up with my tow strap for this very purpose.