I didn't hear from @adanlbenito, so decided to create a BelaMini Symbol and Footprint for KiCAD based on the pocketbeagle layout. I forked the main KiCad symbol and footprints repositories and have provided links below for anybody who wants to give it a try. Perhaps I can figure out how to integrate back into the main repository, but I think there are requirements I probably haven't met. Feel free to contribute/improve/suggest changes.
I should also add that I wasn't sure how to do the symbol, since there can be different configuration of the bela mini. So I just configure pins for the power, digital and audio pins, the GPIOs that I was able to configure and use, and the UART4 and SPI0. Not certain what the correct way is to handle pins that can be changed. But it's really easy to customize so you can just start with what I did and modify for a specific project.
For the footprint, the pocketbeagle had the P1/P2 header pins, which they numbered from 1-72. I added teh audio, lineout, audio out/in and created pin lables for them. Perhaps there are better choices for pin names, so open to suggestions there.
I haven't create a PCB board yet, so I can't say if it works yet. I've added the ability to consume every pin, even the audio in/out, but I'll have to see how it works in practice. I intend to give it a try in the next few weeks. Here are the links in case anybody is interested.