That's great to hear, but perhaps I will ask too much even of the M-series chips.

Occasionally, I will show 3 things at once: an MP4 that the Mac Mini plays from its storage transitioning into captured hdmi signal from a canon camera as picture-in-picture with the main body of the stream containing captured hdmi output from my development laptop.

I'm not sure what my capture solution will be, but it seems there are a wide variety of USB-C capture adapters that I could use that are compatible with OBS on Mac and are even bus powered.

Other comments seem to indicate there are bugs in that specific picture-in-picture setup, but I'm sure those will get ironed out.