This is related, but not wireless, and works only for the Powershot series of cameras:

https://chdk.fandom.com/wiki/CHDK

It is used for DIY book scanners.

I am not a Canon shooter but I welcome really any open source efforts on this front; this is one area of tech where open source is really held back by various vendors' intransigence, API and protocol shenanigans (I'm looking at you Sony)

Is the underlying API same as Canon Connect App