Slings
An advanced sling design would be nice. Loop runners are adequate in a mediocre way, but they don't make your spine tingle. Quickdraws are closer to a super sling in approach, but way, way too short, and I doubt a biner on each end is necessary. There are certain dog leashes out there, but the sewn stitching is inferior for our purposes and lack a captive biner in one end. Some leashes are double-thickness flat webbing instead of tube, and that's getting closer
An awesome, super strong, versatile sling for redirects and light rigging is an everyday tool that definitely makes a difference. Unfortunately, I don't think it exists yet.