Also, even the possibility that the software would send this to the outside would make this impossible to use at my company, and I don't think we are overly strict in that sense here.
Why not? I use it without syncing just for the search functionality which is really useful to me and saves me quite a bit of time. I'm sure the syncing is useful but I don't care about my shell commands enough to want them synced across all the machines I use.
> If you would like to sync your shell history, registration is required. Otherwise, you can use Atuin locally as a fully-offline enhanced history search tool
It does not matter if you think that the website does a bad job of explaining that fact.
Rest assured, that your sentiment, that no employee should be using autin (or any locally installed 3rd party software, really) before a proper audit of the code has been done is understood just by your first comment. A valid opinion anyone can hold.