This is the first update with official contributions from the community! Thanks to @SizableShrimp and @Unoqwy for their contributions!
Also shout out to Mojang for supporting the development of this update!

Changelog

User Preferences

• Added keymaps
• Added import and export for settings
• Added option to individually reset theme colors
• Background images can now be stored inside .bbmodel files

Faster Editing

• Added "Edit History"
• Added "Group Elements" action
• Added bi-directional cube resizing by holding Alt
• Changed how the rotation tool works in local space
• Added option to unfold all groups
• Duplicated elements are now inserted together as a block, rather than in between the originals
• Added interface to use modifier keys on mobile devices

Faster Texturing

• Added gradient tool
• Added option to pick a color from anywhere on the screen
• Added emissive texture rendering mode
• Alt-clicking the visibility toggles now hides everything except selection
• Reference textures in .bbmodel files via relative paths, allows easier transfer of projects between different computers

Faster Animating

• Transform spaces are now supported in animation mode
• Added option to display timeline time codes as frame number
• Added action to set the end of an animation to the current time
• Added feature to automatically flip animation keyframes to the opposite side of the model (perfect for walk cycles)
• Added option to edit scale keyframes as uniform value
• Added animation sample rate setting
• Added toggle to include zero line in graph editor

User Interface Improvements

• Added solid view mode
• Added plugin tags to visually distinguish plugins
• Added distinct icon for discontinuous keyframes
• Made animation list easier to navigate by highlighting the important part of the name
• Zoom actions now work in the timeline and the 3D viewport
• Improved form element descriptions in some dialogs, like the "Create Texture" dialog
• Added ? icon to indicate descriptions in dialogs
• Added option to zoom in the viewport using mouse movement
• Uploading a background now automatically enables background positioning (#920)
• #851 Made vertex snap gizmo for pivot visually distinct from vertices

New Features for Minecraft: Bedrock Edition

• Added option to edit bone bindings
• Locators now support rotations
• Added support for "this" keyword in animation MoLang expressions
• Textures and animations are now automatically loaded from attachables
• Added support for MP3 and WAV sound files
• If bindings exist in model, bedrock model format version is now automatically upgraded to 1.16.0

Other New Features

• Groups now support marker colors
• Added background color option to GIF recorder
• Added option to abort GIF recordings
• New 30° isometric camera angle
• Added option to edit camera angles
• Added Mojang mappings for modded entity format (#900)
• Added axolotl skin preset
• Added edition selector for some Minecraft skin presets

Technical Changes

• Added Canvas.updateView() API to make updating the preview easier
• Added method to highlight an action in the menu bar
• Added option for plugins to require loading before opening projects
• Improved API for dialog buttons
• Add support for custom LaunchSettings option to enable window frame
• Added option for plugins to add translation strings
• Updated Electron to 13.0
• New build for macs with Apple Silicon

Bug Fixes

• Single non-linear keyframes no longer export as invalid JSON
• #893 Broken UVs on planes in glTF export
• Saving animations does not mark animation as saved in some cases
• Switching tools while using the transform gizmo no longer causes unwanted results
• FIxed an issue with particle orientation in particle preview
• Fixed issue with tooltips being cut off at the bottom of the screen
• #464 Plugin actions disappear from toolbars when restarting Blockbench
• Fix toolbars not showing new order without reload
• Using transform gizmo in animation with short interval sometimes edits wrong keyframe
• Outliner toggles are not properly exposed to plugin API
• Hat layer is missing from Minecraft Skin armor preset
• Fixed #886 Extruded Texture only works with 16x16 res
• Fixed #823 Box UV template generation from Per face UV does not generate textures for mirrored elements
• Fixed #936 Undoing "Add null object" Adds a cube instead of null object
• Fixed #934 Plugin API Documentation button
• Fix outdated Photoshop version names when editing textures