I would suggest that the one thing you do not want to take away from a system camera, cheap as it may be, is the EVF. Holding a camera up to do anything with the rear screen is punishing on the arms / hands for any length of time, the more so its there is a heavier lens or a flash unit. If there is sunlight, good luck seeing anything at all. The EVF (or conventional viewfinder for a DSLR) is the one differentiator relative to a cell phone or a point-and-shoot that makes a camera a camera, allowing the shooter to see the picture, the controls and viewfinder info and all good things while stabilizing the camera against the forehead.
This post about the EVF differentiating a "camera" from a cell phone got me thinking. If Canon wants to "woo" the new market of cellphone users into their R FF family, these are the very people who are used to only using the *entire camera-back* touch-screen in daylight or any other light.
So why don't you just
"Give them a cell-phone back screen" and give them what they want. Make it look (& be as bright) as a cellphone, and *easily* interact with them like a cellphone. To them you just have added a R mount FF sensor & lens on it to take stunning pictures.
And, in the near future you could also offer an upscale(much higher price) version of this that would actually
"function as a cell-phone"! Now they really have what they want!
Heck, if you have a entire-back touch-menu LCD that's as easy to use as cellphone users have come to expect, then
I'd be interested in buying it! I could get by on a trip with it and not take my regular cellphone. And it'd inherently have the cellphones GPS to tag all your photos! (of course you'd have energy saving modes if you didn't want it turned on).
If you make it as compact in thickness and screen size as possible like a larger cellphone, then there's
no room for IBIS (whether you'd like it or not). But that's OK - cellphones don't have IBIS anyway! And you have wide pancakes that don't really have to have it, and lots of IS lenses you can add. And no IBIS means you can integrate the sensor/processor/memory heat transfer efficiently to the body so you have no heating issues!
After all, if I take off the lens and put a mount-cap on the body, then it'd probably be pocketable (in a generous size pocket) and still function as a phone. Or maybe I put on a quality thin & lightweight pancake lens (as a kit option!) and it's all thin & light enough that I can comfortably use it as a phone or take pictures/video.
If you
*really* wanted to knock it out of the park, then *
do a deal with Apple* for it to be a full Apple designed iphone merged with a Canon designed R mount/sensor & lenses and let them design the camera processor & user interface! Now
I'd buy it *and* my 2 sons would probably buy it, too!
One thing Apple can do is to make the user touch-screen interface fun, and make it visually stunning and *sell like hotcakes* at a premium price, with the Canon brand riding along as *top camera*!
Of course, you could also
do a deal with another major cellphone maker to do all of this as well.
Call it the Canon "RCP" for R CellPhone, or iCamera (my favorite), AndroidR or whatever.
You'd make a *lot* of them!