The following fixes and features are available on the stable channel:
Features & Improvements
Header and Footer: Add header and footer support to multiple editors
Collapsed Property Groups by default: Allow property groups to be collapsed by default in custom tools (See docs)
Link Editor: Improve input handling for URLs with spaces
Disable Merge Tags Autocomplete: Ability to disable the Merge Tags Autocomplete Menu Trigger by passing "null" to the config (See docs)
Blocks: Improve loading feedback when a block is created, deleted, or updated
Translations: Add some missing translations
Accessibility: Apply ARIA labels to exported HTML of some built-in tools
Bug Fixes
Fix Image Special Characters Support: Fix support for uploading and searching images with special characters in the filename
Fix Merge Tags Autocomplete: Fix shortcut "{" not triggering the Merge Tags Autocomplete Menu when the "mergeTags" callback was set
Merge Tags: Fix merge tags with spaces getting encoded in text links
React flushSync: Fix Preview modal support for calling React flushSync method inside tool exporters