Could the cowls not have the cowl prox switches (to be fitted on the neo and/or retrofitted to the classic fleet) disabled after the aircraft is airborne. Logic connected to weight on wheels....
All these incidents relate to the cowls not being latched on the ground. Therefore, in order to avoid nuisance warnings in the air, sensors just active on the ground. Therefore, during start up, a quick check of lights out etc.
Simple.