Make an extension that could have some more advanced blocks, like 2d lists, better custom blocks, for loops, and local variables. This would be friendly to young or new users because they won't see it and won't be confused, but it could benefit more experienced users too. Inspired by @AonymousGuy 's post https://scratch.mit.edu/discuss/topic/20661/

2d lists have been rejected by the scratch team:

The Official List of Rejected Suggestions wrote:

1.6 2D lists
2D lists, also known as 2D arrays, nested lists, or matrices, are a type of data structure that allows you to put an entire list as an element of another list; that is, it allows you to put lists inside of lists. These sorts of data structures are used widely in other programming languages and functions similarly to a table.

This block, and others, would allow you to create 2D lists to store information. However, this is too complicated for what is supposed to be an introductory programming language. There are workarounds possible by using an ordinary list and an indexing function. For those who are interested, it may be worth checking out Snap!. It is a block-based programming language designed for experienced programmers and has more advanced data structures than Scratch does.

add [] to sublist () of [list v] :: list

for loops are technically already added, but you have to hack them in or get them from an older project, local variables already exist, local variables are just “for this sprite only” variables. For better custom blocks, go to the post you linked above, and please don't make lists of suggestions.