Probably

Using QueryEntityOptional directly with the player properties
Character structs are camera structs in build mode
The FlyCam rotation is not updated in build mode, only the camera is

Fixed prefab update for nonexistent blocks
Removed Type from block placed/removed event args
Added test to check the block ID enum (whether it has any extra or missing IDs)
Added test to place every block on the ID enum
Added test to set and verify each property of each block type (type-specific properties are also set when they can be through the API)
Added support for enumerator test methods with exception handling

Added property to get the camera from the player
Removed pointer magic

Added support for getting the player's current building mode (build, color, config, blueprint)
Added support for getting the current game's mode (building, playing, prefab etc.)

Fixed getting the selected blueprint
Fixed block groups not being assigned to first block

Added a way to store block groups as blueprints
Blocks can be added/removed from block groups, although it doesn't work well atm
Added some patches to the test class in an attempt to debug an unrelated issue
Added a command to test placing a block group
Added a SelectedBlueprint property to the Player class

Removed BlockIdentifiers.OWNED_BLOCKS as the original got replaced with an array
Added the correct group for each supported functional block
Removed EntityFactory property from IEntitySerializer as it is provided on deserialization

Fixed setting player properties
Changed player rotation to float3
Added constructor for BlockColor with an index param
Improved Player.Exists() ~~hopefully~~

A bit hacky, but it works

Placement, movement, rotation, removal
Block looked at (in Player class), connected blocks