I am looking at whether the ATEM Production Studio 4k might be a switching solution for IMAG for my church's services. My question is whether the unit can accept input form a computer (we use an iMac running Keynote for message notes and song lyrics)? I watched a review from July 2013 that said the current (at that time) software/firmware did not allow for a computer input.
It really depends on whether your computer can output the correct resolution/frame rate/colour space. I have had pretty good success using Intel HD 4000 based chipsets (Intel Next Unit of Computing) but I can't comment on your iMac.