Goodnotes 4 finally released with better Jot Script support, and it is tremendously better.
Unfortunately, as I kind of was expecting, while it is better, it's still nowhere near as good as the Touch for writing. It's way more accurate than it was, but there is still an offset that increases as the angle you hold it at grows. If I adjust my grip to hold it close to vertical it is quite good, but that takes a lot of concentration and inevitably my grip starts to slip and then it gets really inconsistent. I also find the ink not to be as 'smooth' as with the Touch - the whole experience, even at its best, doesn't feel as natural.
I would like to re-iterate that everyone's experience will be somewhat different depending on how you hold and/or use the stylus. If your grip is fairly upright, you will have a better experience. If I zoom in even a relatively small amount the experience gets much better - so for someone that doesn't mind zooming and really wants the feel of a regular pen, the Script may be a good choice. I value the ability of the Touch to write in normal pen and paper sized handwriting with no zoom. My experience is that the Script still can't do that.