I have one dedicated inverter
that runs a cold plate (former charter
boat). As I have new batteries and am turning over a new leaf about maintaining them, I grabbed the manual, and found that there is an adjustable potentiometer (wee little screw) that can be turned to raise the low voltage cutout.
I now have a low voltage cutout around 12.3 volts, as well as an egg timer set for 1/2 hour, when I turn this guy on. I usually run it twice a day, when the solar panels
are creating more energy than the stereo needs.
I, too, believe nobody should take their primary bank below 50% capacity if they can help it. I recommend that we all grab the manuals
for all devices that might have adjustable low voltage cutout capabilities, and start "turning the screws".