2020 / 2040 to 3030 Corner Bracket Adapter

So I had a bunch of these 2020 brackets (see picture and link below) but needed 3030 corner brackets so I decided to make an adapter to convert them...

https://www.banggood.com/10pcs-20x20mm-Aluminium-Corner-Joint-Right-Angle-Bracket-Furniture-Fittings-p-1056722.html?rmmds=myorder&cur_warehouse=CN

Remixed from sbucityzero's "The BEST 3030 corners." thing. I made his thicker and customer fit the 2020 brackets.

I printed them as positioned / uploaded without supports. They don't come out