

I use CalyxOS on my Fairphone since 2022. It is better than the stock OS and allows re-locking the bootloader. It also provides timelier updates than Fairphone OS. It is absolutely fine and has zero issues.
I have one banking app that doesn’t work. Another one that does work. Also, I have paid purchases through the Google Play Store that do not see the subscription. I was going to let them expire anyway. I also have a Google One that doesn’t see the subscription, so none of the advanced editing features in Photos works. I assume all of these would be problematic on GrapheneOS as well.
I would run GrapheneOS if I had a Pixel, or if it supported the Fairphone.
Some laptop manufacturers disable functions and stay in low performance throttle if there is no battery present, and remain that way until a new one is installed. Apple does this.
Some laptop manufacturers disable features if their operating system is not installed. Apple disables integrated Intel graphics, for example, and forces amd graphics on Linux and OpenBSD.
So its not impossible that your laptop is crippled by design without the battery.