rhenwood's comments

The Arm laptop community for these higher-end cores in laptops is currently active here: https://github.com/aarch64-laptops/build

+ You can install your own OS. + Mainline Linux boots, with some caveats. + There is an Ubuntu 18.04 patched installer that works as expected, but support for the platforms isn't in the main distro installers yet.

One correction: Unlocked boot loaders are still present. All the platforms that I have seen that support Windows on Arm have boot loaders that can be unlocked.

This is probably the best place to follow machines that have unlocked boot loaders, as currently Linux enablement requires it: https://github.com/aarch64-laptops/build