Customizability, and most importantly portable customizability, is non-existent in most modern software. Even highly configurable FOSS products like Firefox take time, effort, and above average technical skills to mirror configs between not only clients, but identical clients, and even to keep them in sync. You should just be able to export a config file and import it onto another machine, if the versions are identical.

As a consumer, I often wish that there were a requirement for ALL digital product software and services to export/import their current config, including all user data, to open-source compatible, lossless formats — this would be the most effective method to free consumers and businesses alike from vendor lock-in and monopolization — but as a developer I’m aware that would be a nightmare, especially for all pre-existing software.