Any idea if the EOS M is supported for this? Last I checked Magic Lantern had no webcam type functionality but that was ages ago. If it does that's a pretty great webcam for like £100
RE those chinese knockoff dongles, I got one for £8 off ebay, use it for Pi Zero stuff occasionally and the lag isn't bad at all tbh. I'd guess somewhere between 250ms and 500ms but it maybe gets worse at larger resolutions.
I have an EOS M and it works ok. I had to install a different version of Magic Lantern to get it to not auto shut off, and generally a lot of poking around in the menus. You can get battery replacement AC adapters quite cheaply and my cheap HDMI->USB works fairly well. Lag is not a problem but it introduces black bars on the left and right and in Google Meet my feed is horizontally squashed. Other video apps the picture is fine though.
RE those chinese knockoff dongles, I got one for £8 off ebay, use it for Pi Zero stuff occasionally and the lag isn't bad at all tbh. I'd guess somewhere between 250ms and 500ms but it maybe gets worse at larger resolutions.