been happily using chezmoi (https://www.chezmoi.io/) for the last 4 months. One of its key features is the ability to generate configurations from templates, which I've been using to maintain similar-but-slightly different configs on macOS, Fedora, and Ubuntu/WSL2. Also has the ability to run a script to provision a new machine, which is a nice way to install the base software you want everywhere (tmux, vim, git, etc.)
edit: typo