cameras with s35 shooting modes on larger sensors

[Robinhood]

Hey everyone

I currently have a 5diii (which is FFVV) but i'm looking to do an upgrade in the next year or so

I'd like to get a camera that has different crop modes available for both stills and video modes  -- For example, I love the fact that the Canon 1DC is a FFVV camera but has a s35 mode to switch to in 4k 

What cameras have a similar function?? Getting a Medium format camera that has both FFVV and s35 crop modes, to do quick switches down to, would be fantastic. Looking into Fuji....anyone know if the GFX50S or R or the new 100mp camera will have these options? Other brands with this function I am open to as well

Basically, I figure it best to upgrade to a larger format which has smaller format crop factor modes in a camera that just use less of the sensor rather than buying an additional camera rig like an APSc rig such as the Fuji XT3. The less separate camera rigs the better

let me know 

[Nocturnes]

Sony A7 Series is your only other contender, I use the function daily for extra reach on a single lens.