They're truly scraps, just the cat cutouts. Do the numbers; the hex tarp use just 7 yards because Lawson switches middle and outer edges to minimize waste......and reduce cost to buyer.
I might want those strips, too, for reinforcement. But, then, the price for cutting may reflect their value to Lawson's.
Suggestion: Buy an extra 1/3 yard for reinforcing strips. Cheap enough.
But, find a pdf by suluk46.com testing bursting strengths of cuben tarp tie-outs, which suggests to me that (as with UHDPE cordage), there's an issue with dynamic resilience in wind gusts. Reinforcement strips will not easily change that.