Really though, the RPi's config.txt is exactly this kind of rabbit hole. I just got a Zero W today and now I'm thinking about if it's possible to underclock it enough to power it with a lemon battery via GPIO.
It used to have significantly more performance problems, but it's always followed the basic form of "tiny PC with IO pins and overbearing GPU".
According to this video I’d need a wall of lemons to get 5V with support for 300mA of current: https://youtu.be/a1D-fZP8qJk?t=205
So it may take some... adjustments... to get something like this to work, but I’ll see what I can do.
Of course computers (including mobiles and tablets) became widely mainstream over the years so the percentage of tinkers dropped but the absolute numbers increased.