In case you need your heart broken, there's evidence to suggest Scratch Team were seriously considering allowing blocks to placed inside of variable dropdowns.

Evidently, that fell through. Something didn't work.

First look at a redesigned Scratch Cat, possibly for 4.0

Let's play a game! Which one of these was rendered in Scratch 4.0 and which one was rendered in Unsandboxed?

Global custom blocks have been released for Unsandboxed.

Full changelog in the article.

If Scratch-Blocks 2.0 was nicknamed "spork" during development, what should I call this? spatula?

So I can say for certain that Scratch 4.0 will depend on modern Blockly, which for now is being held together by the old GUI code from 3.0

Useless Scratch facts # 2:

spatula inline blocks (broken for now)

An update has been released for Unsandboxed.

Changelog is in the article.

Useless Scratch facts # 1:

The order of the motion category blocks in Scratch 3 was changed from how they appeared in Scratch 2 in the 11th hour.

In the Scratch-Blocks 1.0 developer testing playground, the order is identical to Scratch 2.