As in the first part of the answer immediately above, the ‘reset’ is handled by setting the $KeyAttributes attribute:
To clarify, the actual action is to set no value, i.e.
But even if there is no following action, people tend to add a semi-colon regardless as in the first example. Both actions do the same, but the former makes it clear that this is the intent and not just a part completed action.
For quick-stamp, there is a button to reset inheritance - see here.
I’d suggest a rule is sub-optimal for this task as it only needs doing once, better would be to use an edict for automating this. Or, use an agent that only matches DT-generated notes with the ‘wrong’ KAs and thus do the reset function only on those notes that need it.
However, bear in mind that notes created in a DT watched group are assigned a built-in prototype called ‘Imported From DEVONthink’ which sets DT-related KAs by inheritance. Thus you may not need a ‘reset’ at all but simply to apply a different prototype and let inheritance set the desired KAs.