Hi Marc, I finally got SAC to show us his solution for the floor bounce.
Here it is.
He reckons two 'broadband' panels as in the diagram should do the trick. Apart for the very obvious problems with these things in the way, I claim that even the two in tandem will have no significant effect on the dip you are experiencing. I have offered test this here, but it would make more sense if you did it. After all it is you that has the dip and this is SAC's suggested solution.
Let's prove it or rubbish it in situ, in the real world.
DD