I understand that many dapps have off-chain data that cannot be captured for DAU, but... delegations are on-chain data, and non-zero delegation actions should be included. (i.e. if a delegation remains untouched, that might not be an active user - it could be somebody that forgot about it, and if a delegation is set to 0, that's potentially a 'departing' user, not an active user, but if a delegation is set to something other than 0 that would usually indicate an active user)