Battery (really solar panel) Disconnect Question

The Morningstar manual says it is an NEC requirement to have disconnects on the array and also on the battery side. It seems more like a safety issue with the high panel voltages. They also say the controller can be damaged.

There is also the need with 12/24 controllers to first connect the battery to let the controller learn what system voltage is before connecting the array.

I have had my controllers on array but not battery at times with no issues, but maybe just lucky.