My zsh/nvim/... dotfiles are portable and compatible with FreeBSD, macOS and a bunch of Linux distributions, but it's absolutely unacceptable to run those on a machine I don't control. You don't mess with configuration on another guy(ette)'s server.

My setup is customized, but the core experience is kept relatively untouched. If someone experiences a problem, I need to be able to debug it in place efficiently. I write drivers for the company's hardware for a living—troubleshooting takes more than 10 minutes.