I would say the concept is similar, but the execution is different. It looks like the 260 has a decent place to locate those bars on either side the keep the mast aligned. On the 26.5, there isn't a really good place that is in line with the pivot point at the base of the mast. My solution was to build a bridle that ties into the lifeline stanchions fore and aft, and then comes up to a point that closely aligns with the pivot. This allows me to get the most distance laterally from the mast for the baby stays. The whole system is then in tension during the entire raising process.
I hadn't thought about dyneema, but that would certainly be easier to stow when not needed. I'll have to look into it. The working load on this whole system is very low (with the exception of the forestay), so heavier gear isn't really necessary.
GH