Download 16.1 RC?

Hey @gezan – great question.

Release Candidates (like RC1) can be downloaded from Github – although I admit they can be a little hard to find.

All releases can be found at https://github.com/WordPress/gutenberg/releases/ (including release candidates). You can specifically find 16.1 RC1 here:
https://github.com/WordPress/gutenberg/releases/tag/v16.1.0-rc.1a

At the very bottom of that page, under the ‘Assets’ section, you’ll find a download link for the ZIP file of that version. Please give it a try and see how that goes.