I think it should be Net 1 but with 2 inclusions minimum (i.e. like the current formula but bumped up by 1).

One inclusion, no exclusions - not in DT2.
Two inclusions, no exclusions - in DT2.
Two inclusions, one exclusion - still in DT2.
Two inclusions, two exclusions - no longer in DT2.

And so on.

This would reduce the chances of (lone) rogue "includers" and rogue "excluders" from messing with the system (self-scratching etc).