I adore the differences between conan and haibara's experiences with shrinking
the aptx put shinichi's life on hold. everything is way less convenient now that he's 6 again, not to mention the fact that even if he got his body back, he wouldn't have his freedom back since the org still thinks he's dead!! his life will never be the same, but despite that he's still fighting to get his life back to the way it was before
meanwhile, haibara was trying to end her life by taking the poison. the fact that she survived was very fortunate (questionable if she would agree with that). she wanted nothing more than to escape her previous life, and disregarded it many times. the bus hijacking is a prime example of that. it's only after conan saves her that she starts to understand she's allowed to have a life separated from miyano shiho, from sherry. being haibara ai opened a new door for her at a time she thought there was no exit.
shinichi wants/needs constant reminders of who he actually is (keeping in contact with ran, having everyone in the know refer to him by his real name when safe, etc.) even if things would be so much easier if he embraced conan's life more. haibara is the exact opposite, she is fully haibara ai now, focusing her time on haibara's relationships and life.
miyano shiho is haibara ai, but kudo shinichi is not edogawa conan. haibara ai is a new identity, a name to match where she currently is, whereas edogawa conan is an alter ego, a separate being, just a facade for shinichi to keep up until he can return.
it adds so much to their dynamic, where everything haibara puts into finding an antidote is purely for shinichi's sake. meanwhile I don't think shinichi even fully understands that haibara's perspective is different. it makes their interactions that much more layered, along with how they act as their elementary school identities.
