Great timing, I was just getting frustrated about this today. I've got a pyinfra secrets.py and another project with an .env for logins for grabbing and moving data. I use LLMs on both of them extensively (having an LLM setup all my proxmox VMs and LXC containers and configure them without doing that yak shaving has been amazing.)
It would be nice to use something like SOPS[1] + age right from the start, so I don't feel like I need to go rotate all those keys.
It's one thing to have it stored locally on your own box, and another to have it off in the training data of a hugely-overvalued gigantic corporation that's going to do anything it can to survive in the coming years.