I'll explain my reasoning for doing the snapping the way it's done, and why I will keep it the same:
1) First of all were talking strictly about the extra diff here. I'm sure we all can agree that a stream adds more difficulty in a map than a 1/8 or 1/16 single repeat slider. So to fulfill the role of being an extra, it would be more reasonable to use the harder solution here since it does fit the music and is an easy to understand rhythmwise aswell while playing the song
2) Now to elaborate on that note a bit further; no, the hardest solution possible isn't always the best one, but in this case it is much more fitting than a repeat slider which follows the music more closely, but at the same time is being completely underwhelming with it's difficulty
3) For why I decided to map the streams instead of only following guitar and using long sliders is partly connected to my previous reasons but for the most part it has to do with the great presence that the piano has on the parts. It would be weird to only use long sliders that follow the long guitar sounds well while ignoring the piano, instead of trying to map the piano sounds into the most appropriate and enjoyable way to play them, which are streams in my opinion in this case. I can see why you'd find 00:25:613 (5,6,7) - particularly worthy of pointing out, but since this is a rhythm game, ending the stream on a blue tick would not be the most optimal solution here in my opinion. Thus I decided to extend it on it's own to a more easy to follow and fun to play rhythm that is made up entirely by me, but still fitting the part and the song nonetheless.
4) Following my experience from the playtests and the 4 day period that everyone has had to play on the qualified version, I've had only one complaint about the streams from the user who posted on this thread, but no one else has atleast publically spoken of them being unfitting. What I can take away from this is that people find it natural to play for the most part as intended and have no complaints. This further proves why I feel like my actions are justified and why there is no need for anything to be changed.
I hope this helped explain my thought process a little bit