How long do you have to cook adzuki beans in a pressure cooker before they're edible?
Consulting several sources about Adzuki beans (see below) they shouldn't take any special time to cook, about equivalent to Navy beans.  Normal cooking times should be 15 to 20 minutes for non-soaked beans at 14 PSI / 90 kPa.

However, you cooked them at low pressure, which is usually 7 PST / 45 kPa, and is too low to make much of a difference in bean cooking time.  I don't know how long they'd take to cook at that pressure, but I suspect it's not much less than they take to cook with no pressure at all.  That is, you'd probably have to cook them for an hour or more at that pressure.

Sources consulted:


Lorna Sass's vegetarian pressure cooking book
HipPressureCooking
MissVikie