That's an issue I've been having with a lot of Japanese acts I'm obsessed with: listening to the singles to death, months ahead of the album's release, and then feeling kinda disjointed when finally hearing the album because I already know a lot of the songs by heart. It creates a sense of 'imbalance' that can be jarring (for example I had listened to "Image" more than 50 times before the album came out, now I usually skip it when I listen to the album). It definitely takes quite a few listens to view the album as a whole rather than "old songs + new songs".
I've also noticed that Rina's drums are very different on some of the older tracks (like "Departure" or "Yoake no Ryūseigun"), where they sound a bit flat, simplistic and robotic, as opposed to most of the new tracks like "Your Song" (now quite a new song though), "Love in Action", "Graduation" or Onegai Navigation", where her playing really shines and is even enhanced by the clear production. It makes the contrast even bigger, like she had a quantum leap in her drumming chops in just a matter of a few months.