I've done a lot of deliberating about where to use a rated (24Kn) screwgate, aluminum carabiner, in a climbing system. I've used it combination with both Weaver and New Tribe endless loop slings, in basket configuration, to redirect my primary climbing rope. Of course, it proved to be adequate to safeguard against a swing into the tree trunk, when I tested, low and slow. Also, I "gate check" after installing the sling and screwgate in the tree to be certain that all components are configured correctly, including that the screwgate is "extra hand-snugged" and the carabiner truly locked. Question #1: Is the redirect gear system I described above "below standards"? Question #2: Would a screwgate carabiner be suitable to build up the false crotch, as pictured on p. 63 of "The Tree Climbert's Companion, by J. Jepson, 2nd Ed., instead of the double-locking carabiner, pictured and documented there? Question #3: Has there been a study of, probably non-_meta_llic, add-on components that would serve to make a strength-rated screwgate carabiner vibration-proof and reasonably un-thread-proof?