I see that N1 is still in the works, so I recognize that this should be the priority. However, I suggest adding further methods of dividing and categorizing grammar points. Maybe something like a “conversational path” that builds off of frequency lists of spoken grammar and vocabulary. Then, this could be complemented by a “literary path” for those who are more inclined to read than to speak. Maybe you should consider a TV/anime/movie path too. Once all of the content is created, it could be further categorized beyond the JLPT levels to allow for alternative sorting and paths like this.
Also, while it’s great to have broad knowledge with a variety of grammar points, we end up with numbers in the double digits for something like “can’t help but” when only one or two would probably suffice for most language learners. Then, the less frequently used versions could be studied later. Basically, what I’m saying is that while JLPT should continue to be the clear point of focus, I think the program should be expanded to allow for students with different priorities. The content doesn’t need to change, just the categorization options to allow for a more efficient focus on what will be most helpful most quickly.