Flagon - In ref. to your initial suggestion (nš 1 above)
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In the 747 check lists "Before T/O" (which we initiate when we exit the ramp for taxiing to the active runway) we need to have the flaps selected to the T/O position, so that we are able to complete the "FLT CONTROLS CK", also part of that "Before T/O" - If flaps remain UP, our outboard ailerons are remaining faired, making it impossible to check flight controls. Was the same in the 707s and 727s I previously flew...
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The "3 killers" trim-flaps-spoilers is not a recent "invention" - with PanAm I recall it as being an "old practice" by the time of my initial training in 1969. Would suspect that the PanAm "3 killers" originated with the first jets (707s and DC8s) - I have flown for many different operators, worldwide and was crewed with pilots/flight engineers having different backgrounds. Many seemed to "know" the "3 killers". Some operators add "compass/heading". In the 747, there are extra items that would trigger a configuration warning, such as BODY GEAR SWITCH - and EXT GREEN BAND SELECTOR SWITCH, which makes it 5 or 6 items...
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You are NOT assured that the T/O warning horn will operate as designed if you are not configured for takeoff.
It possibly saved my neck twice...
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Happy contrails