Is this the Github of it: https://github.com/linux-pam/linux-pam ?

Could I pam_time root or something that has a higher rank and a different password then my main user?

It all depends on how “forced” you want to be.

I would say: It should take at least 3 minutes (better more) to circumvent it.

Generally, in Linux, if you’ve installed it, you have the power to uninstall it. Once your lockout gets put in effect, you can boot from USB, mount the hard drive, modify the files necessary to bypass your lockout, then reboot and proceed as if your lockout didn’t exist.

This sounds like it would take me around 10 minutes, so its enough for me to stop and do what I should be doing instead.

So I can’t stop it or change it because it has a higher rank and a different password then my main user?

cron job that launches the lock screen at the specified time and unlocks it later?

Is there a way to only allow changing it when entering a password (that is different from the user password)

I prefer Fedora over Ubuntu because they are more up to date and put Flatpak over Snap.

But the real reason I originally switched was that the Ubuntu installer crashed 5 times in a row and then I tried Fedora and liked it

I am not so much into programming, but what extra skill is required to add a license and make the repo public? Maybe if you have a closed source dependency and would need to replace it, then it would be a skill issue.

Are there any relevant/common reason to keep an app closed source if its NOT for profit?