In the post I referred you to, the author was using Hikvision cameras. You can see all the variations he tried with and without Stream enabled and the effect it had on video lag. He was also seeing ~13 sec lag with Hikvision/Stream.
I also refer you to this reply from the developer on tweaks that should help…
Those tweaks can be done via the Hikvision camera web UI, but since I don’t have these cameras, I can’t offer any other advice on what to try.