Posted as per @Loran's request. Fits base platform: https://www.openhardware.io/view/22651/Version-10-atmega328p-test-platform

I have tested this adapter, and it works.

I posted the complete KiCAD 6 archive for this project. It is the .rar file under this project's "Files" tab. That means I'm not a bottleneck. Anyone can open up the project and pick up exactly where I left off if they want to make changes or fork.

Inside the .rar file is a zip file. Don't unzip the .zip file. Rather, in Kicad 6, under the "File..." menu, go to "Unarchive project...." and give it the intact .zip file.