Don’t think too many have used virtual training for Jumping so might not generate too many responses.
Jumping is a little different because a rider miscue can result in a stop or runout that can quickly become a habit if not corrected instantly. Or the rider coming off. Or both. A trainer/coach/experienced person standing right there can correct the mistakes instantly or better yet, before it happens. Prevention being the best cure and all that.
Might help a rider with more correct flatwork, correcting position flaws and even work over poles and very low x rails though. Just not blowing a distance burying a horse into the base and going through instead of over an oxer or horse sucking back to a stop at a spooky round top. These things need personal, in tne moment correction to prevent them in the first place, not dissecting why off a video.