I know one or two people at the Commission passionate about Linux that indeed have small use cases for NixOS. Awesome! They have all my support!
To my knowledge, the use cases are not business critical.
It would be nice to learn more about the use of Target, Shopify and Mercury. Do you have sources? A blog post, Youtube video or something like this? Is it well Linux on the desktop? How many users? Only developers or also non-tech staff?