Madaidan’s Insecurities hasn’t been updated in a few years, so some of the information is a bit out of date. It is still decent information, but don’t follow it granularly. What you may be looking for instead is secureblue, which essentially does what you are describing but for Fedora Atomic desktops.

Thank you! I will try this tomorrow. I’ve been at this for 7 or 8 hours straight now.

I think so, but I can’t be certain. Is there an easy way to check?

I specifically need CoreOS since I plan to rebase it to securecore. Thanks for the suggestion, though!

Yes!

My list of open source software lists LibreTrack as an open source delivery tracking app for Android and Linux.

I will never by a portable device without a headphone jack

You can get 3.5 mm to USB-C adapters for relatively cheap, or buy direct USB-C wired headphones. GrapheneOS allows you to restrict the permissions of the USB-C port to your needs. Alternatively, just use wireless earbuds, if you don’t care about the security issues with Bluetooth. GrapheneOS also includes automatically disabling Bluetooth after a timeout when it’s not in use.

In my opinion, the security benefits of GrapheneOS far outweigh the need for a 3.5 mm headphone jack.

Instead I am currently trying out Sailfish OS on a Xperia 10 to use Linux

Linux phones are wildly insecure.

I will continue to use Proton and their services, not because I support or endorse any political decisions from the CEO/board members (and I don’t), but because they provide open source, secure, and private software that I love.

This is no different than arguing about using GrapheneOS based on the behavior of the maintainers.