“The good thing about standards are there are so many to choose from!”
IMO GOUT (NTSC GOUT to be precise) meets the “good enough” standard, and I’m for sticking with it forever. Adding a frame that was never actually seen in theatres would break sync for all projects (not that it would matter for subtitles, but I’m thinking of others), for a pretty esoteric benefit.
There’s a better argument to be made for matching theatrical prints, since they have fewer frames than the GOUT, but it does not seem that they do so in a consistent manner, so there’s no standard that would apply to all prints. And losing those frames would also break sync for all projects for a pretty esoteric benefit.