2) Are they supported "fully"?
2.1) Can you for example boot from such a GPT partition?
Thanks
[1] quote from: https://reactos.org/project-news/reactos-in-2020/
Kernel and drivers
As there are two developers working full-time in this field, there are quite some long-awaited changes:
Merge of the PnP storage stack. The new storage stack, derived from open-source Microsoft drivers came to replace the old NT4-compatible ReactOS storage stack. For a long time many workarounds were applied to make the NT4 storage stack work in the NT5.2 environment. This era ends now, with a major step forward in compatibility with modern Windows, along with new features:
- GPT partitioning support.