Hey cool, a relevant place to mention my project: https://dotprot.dev/
Type "dotprot" to copy your .env file into 1Password using the 1P CLI, it verifies it's there, then deletes the local copy of .env. When you're ready to work again, type "dotprot" again to restore the .env file from 1P. There is a .prot file in the directory that you can declare other files to store in 1P as well.
Varlock (https://varlock.dev ) is also good for this and more mature. I use it on some work projects, but for local dev, I wanted something to allow me to be even lazier than that.
If 1Password hadn't jumped the subscription model shark, I'd be all over that. Any chance you'd entertain supporting bitwarden?
Varlock has bw plugin too - and similarly you can either wire up individual items or pull a whole env style blob from a single item if you prefer.
FYI - You can pull a whole .env style blob from a single item using varlock. Never written to disk and supports caching behind Secure Enclave.