You have to stream your event at 3-4 Mbits because of the venue’s network limitation, but you’d like to record in higher quality as well in the same time without additional device.
Add one short HDMI to HDMI cable to your setup.
Set your HDMI OUT 2 to Program.
Plug in your HDMI to HDMI cable to HDMI OUT 2 and HDMI 8 IN.
Turn on ISO recording.
Another trick is, if you’d like to record you’re SuperSource instead of high quality Program, then set your HDMI OUT 2 to SuperSource and connect to HDMI 8 IN.
You cannot record both (SuperSource and Program) in same time in high quality with this solution.
Note, this only works with ATEM Mini Extreme ISO switcher.