I couldn't give you the cooking time, but with any moist heat cooking method, the Instant Pot shines. A Boiled Supper or your Cabbage Soup would do well in an IP. My Daughter gave me one last Christmas. We use it pretty frequently for any dish that does not need to be reduced to thicken or concentrate flavor. Yes you can take the lid off a simmer but then you lose the seedy cook advantage...JJ
I always thought of them to be a speedy crockpot. I’m looking forward to hardboiling eggs with them, although the steam method on the stovetop is a pretty good method as well.
Lots to learn and research!