Blackmagic setup: How do I record all cameras in a multicam broadcast?
You can use an SDI Distribution Amplifier ("DA") (one SDI input, and two or more SDI outputs) for each camera so you can "duplicate" the camera video to send to both the production switcher and to your camera iso recorders. I use DAs I buy on Ebay.  My current favorite is "AVUE 3G-SDI/HD-SDI/SDI 1 to 2 Repeater &amp; distribution extender with re-clocking" at around $100

Or you could use something like the Blackmagic Smart VideoHub 12x12 if you have the budget for it.  Of course, you will need a separate recorder for each video stream. It seems unlikely that you can successfully use more than one UltraStudio Mini Recorder per computer.

The camera has a built-in tally light and the switcher sends the tally signals back to the cameras (assuming you use TWO SDI cables per camera!)  The tally light appears to be quite small and hidden just above the lens mount, so it seems of limited visibility unless you have a very small lens and are very close to the camera. There does not appear to be any kind of output for an external tally that can be seen at a distance one would expect in the Real World, or any tally provision for a camera operator. Are you planning on using these as human-operated cameras?  Or remote-controlled?  Or fixed POV cameras?

The Micro Studio Camera 4K has intercom built-in, with a 3.5mm TRRS socket for a headset as one would use with an iPhone, etc.  However you will need an ATEM Talkback Converter to access the intercom/talkback back at the switcher end.

Remember also that those cameras do not come with lenses, and they use a rather premium lens mount, so you may end up spending 2x or 3x for each camera by the time you hang some glass on the front of them.  The Blackmagic stuff seems like great performance for the money, but not necessarily when you add up all the required "accessories".  Especially if you want to equip the camera(s) with operator-controlled lenses. You could end up with 4x-5x the base price for each camera.

Remember also that SDI is quite high frequency and doesn't tolerate "very long SDI cable runs".  My working rule is that even with large RG-6 cable, 300ft/100m is the practical length limit. If you want to go longer than that, those fiber optic boxes from Blackmagic are one solution if you have the budget for that.