Boeing 767 DDG quotation "Upon completion of any applicable procedures and prior to takeoff, the operator’s MEL should be consulted to determine if relief is available for continued operation with system faults displayed at the alert level (Warning, Caution, Advisory).", so Boeing's policy is: if after or during engine start and before TO there is an alert message: 1) do the respective non-normal checklist (NNC), 2) check the DDG or MEL to make decision. For me, it is still unclear what to do if on this stage and before ETOPS entry point there some issues related to ETOPS MEL ITEMS and which usually not considered for NON-ETOPS flights.