how much tuck behind wings

What would be the difference in feel between a ‘normal’ shortboard wingless HPSB type of  tuck behind the wings, and a full on down rail behind the wings on a double wing round pin on a 6’11" x 22 x 3" speed egg?

 

I’ve not found much in the archives on this but could have missed a gem of a thread, like the one spent hours reading last night on multifin thickness.

 

 

if I understand your question…none.