Not sure about the laptops, but the keyboard is nice. My guess would be that the percentage of returns will likely be similar to lenovo but they have logistics covered in most countries. S76 should simply not sell in countries with prohibitively expensive return costs.

How would they enforce this on open source projects without companies behind them?

This doesn’t require the user to be able to block, it’s required that there is the ability to block a user from the system in general.

Here is the official list of nextcloud providers that do the setup and maintenance for you: https://github.com/nextcloud/providers#providers

I’m using fedora as my work system, because I have a relatively new laptop that needs the new kernels. Haven’t experienced anything you’re describing. Are you on fedora regular or on sliverblue (the immutable version)? If you’re having issues running the newest kernel, follow the fedora documented way to build and run your own. I did just that when needed a prerelease kernel and it worked out fine. I usually upgrade to a new release by the end of the cycle, so that the new version had 6 months to mature. I never immediately upgrade.