Definition: “flat-iron bow” = Your normal lid-bow (of flat iron?)
Flattering: When the lid goes “fast-wobbling” by
the gaspressure / feather-power cycling.
letting lid-opening can be rotating around the lid-edge too
A lot of patterns can develop, as the
"down-pressing" point is above the supporting surface!
Lid stability: Wobbling or not, perpendicular to the feather-bow.
You are like a cat walking around a plate of hot porridge!
The lid instability resambles that of a parachute!
The weight = spring power has to be pulling the lid down against the flow!
In the streaming flow direction: Weight = feather power first and then
the “parachute” = lid surface.
The feather bow is “grounded” longitudially
on the invisible line: Hinge—lid-lock.
If this invisible line goes below the lid-seat-center,
the "parachute-stipulations are “fulfilled”!
The stability applies in other horizontal directions too!
Whatever you do with the “grand” feather-bow,
above the invisible line Hinge—lid-lock, it does not affect the geometry:
Only the distance between the lid-seat-level AND
the invisible line HINGE—LIDLOCK affect the stability!
No mainipulations on the lid-dome affect or contribute to the stability!
The final adjustment is to set the hinge and lidlock on the right level
relative to the lid-seat-plane.