i would like to point out that the luke route graph is character specific one, and the more generic content ones in the example might not be fair for a direct comparison.
personally i will be fine with the saves backtrack. but am i correct to assume other characters should also get their hangouts started by chapter 14 or once they join the staff? if we can't get a work around it, maybe you can introduce save point recommendations to the moments in the story you still plan to expand on.
other than that, let me tell you kota's new visual is looking great and i'll bet he will see an increase in popularity. also completely agree the optional characters didn't get enough scenes to have a good feel for them for readers to form an investment. here i'm looking forward to properly getting to know them.
and thanks for taking different time zones in consideration. i see a lot of times in the internet when people give out a schedule and then i have to dig in to figure out what time zone that they meant.