Interesting that the R8 has a mechanical second curtain shutter, yet they don't use it to protect the sensor when off. I'm going to guess that one was marketing driven, to not make the R8 too appealing.
The only EF-S mode mentions I could find anywhere were all about using the 10-18mm for vlogging. I couldn't find a single still image. I know it's a niche feature, but that was surprising.
I looked up the Fv mode. It's basically you choose one thing, the camera auto selects the other two. So it's 1) Av+Auto Tv/ISO, 2) Tv+Auto Av/ISO, or 3) manual ISO+Auto Av/Tv, with the camera auto selecting every creative option, ie. DoF and motion blur. I'd still prefer to choose the creative parts and let the camera select just the exposure.
Maybe Fv is smarter than the old sports mode which used a fixed 1/60th shutter. I can't remember if this baffling choice was on the Canon T1i or the old Sony H1, but I lost any trust of camera firmware authors after that. Perhaps with the AI subject detection it chooses an appropriate shutter speed, but what does it consider appropriate? No blur? A bit of blur on something fast? What makes the DoF appropriate? It doesn't know if I want an isolated subject. Nah, I'd rather pick.
Since Auto ISO was already a thing, the only real new option it gives you is manual ISO + Auto everything else... which is green box mode with a random Av or Tv change applied to compensate for your ISO choice... Or am I missing something compelling?
Adding further wrinkles (that nobody can help with) Magda wanted something light, as the old 1Ds2 hurt her hands. She also requested a zoom faster than 2.8 since she became aware such a thing existed... The two requests seem mutually exclusive on Canon mirrorless, as the RF 28-70 f/2 seems to be the only option, and it weighs the same as the 1Ds2 did. Maybe I need to invest in helium lens coats.