For assistant scenes in s7 unpack the attachment into "C:\Users\{UserName}\AppData\LocalLow\Bokuman Studio\Waifu Hub S7\NaninovelData\Saves".
This will replace your first 4 saves to a save of the first line of each assistant's scene. Since instead of unlocking those the proper way by going through an interview I ended up just hacking my way into each scene, if once you load a save you go to Phone menu it won't let you get back into the scene. The only problem with this approach is that you're kind of stuck with the default background music instead of a randomised one.
Also since no one asked for anything specific, I've set MC name a placeholder from game files which happens to be Jordan.
Edit: For the background music, there's a workaround, all you have to do is go into a different interview until you get a track you like, and then load the save. The game stays stuck on the current track when you load save files.