No flatness observed
Many years ago an old instructor told me a tale of a spin that he got into intentionally, and after several attempts to recover he was below 1100 ft agl
(The spin entry was 5500). He was convinced that he was in for a prang.
A last second thought to slow the pa38 up, he applied flap.
He comments was the spin stopped so abruptly he nearly cricked his neck.
It is a valid thought and I have kept it in mind but to date have not had to try this alternative recovery method.