Hi…there is an exceptionally decent KiCad model accessible. I don’t think it is advanced science to make something straightforward utilizing a CM4.
However, after I took a gander at the Compute Module IO board there is no sense in building my own. The technicians is truly astute and you can undoubtedly make HAT style sheets that have connectors on the left and inverse side of the board as it were. The Audio injector sound card would fit consummately giving both sound in and sound out. In reality most HAT cards would have a pleasant mechanical spot to broaden usefulness. So investigate these befor taking the jump to make your own.