Sorry that's not enough evidence, it's very unlikely that CIDER places a hook on Emacs focus-out. You can always create an issue in https://github.com/bbatsov/prelude chatgpt is also surprisingly good with all things Elisp.

https://github.com/bbatsov/super-save

seems to be this

Thanks!

https://github.com/bbatsov/prelude/blob/master/core/prelude-packages.el#L91

Looks like it's got a (save-excursion) special form built in, I need to investigate why it's not working