Pretty sure that on my 2012 XC70 the ABL works with the headlights in the "0" position. This evening when it gets dark I will experiment to see what are the operating parameters of the ABL system on my car and report back.

ABL did work in both 0 and "on" position in my car too, to begin with. The difference then was that when in 0 position, you couldn't get high beam to "stick" unless it was dark outside.
The current principle of operation my car acquired in association with a service and the attached software update package.

Well my ABL worked in both "0" and On positions but I didn't know about the high beam settings so I didn't test that. It will get dark this evening so I'll be exploring the realms of headlight software development!