Reminder this is another non canon and glorified fanfictions serve as a bait that Typemoon always allow to boost sales. Similar case with the lb6 situation before.
The tablet of contents in that book said this is non canon personal interpretations from the artist.
This route already has a faithful adaption before. No need to delve into it more than they want to sell this as fanservice under as "new thing". Released right before transition year too to finally close FSN era up for something else.