It’s relevant to note that the Snap release isn’t officially supported by the Atom developers. Since Atom is open source, it’s easy to redistribute it on other platforms and the devs don’t have to personally support all of the potential ways that someone could download it. That also means that things could go wrong in an unofficial distribution like the one in Arch community or on Snap (this has happened on Arch, and it took a few months for new versions of Atom to actually work on all updated Arch distros, which was annoying since part of the ethos of Arch involves constant updates) that aren’t going wrong with a core distribution, and since there’s a third-party developer in the chain, it’s impossible for an Atom dev or community member to account for everything that went into compiling the code you downloaded.
Atom stores all of its configurations and packages in the
~/.atom/ directory, so unless you specifically override that folder (by putting a
.atom/ directory in the folder that contains the
atom/ program directory to use the mobile mode), all instances of Atom on your computer should look and feel exactly the same.