Nice update... and definitely good to know.
As a side note, there are several things that can be done to increase chassis rigidity if you did end up wanting to remove the bracing again, and for those that don't already have it. For starters you could fill the crossmember channel under the bracing with automotive structural foam. It can be had in varying degrees of firmness and I'm sure that it would make a significant difference. This was my eventual plan with my old EJ6 (that didn't have the bracing). Also, I did notice that it was fairly easy to affect and improve rigidity and handling on that car. I felt a significant improvement when I Dynamatted the entire car, specifically when I did the floor and rear hatch area... more so than when I added the coil overs and camber correction kits. Having said that though my EJ6 with full Dynamatting, coil overs, camber correction and dropped ride height couldn't compare to the feel and handling of my EK9 that's currently on worn out stock EJ6 suspension and no rear sway (both soon to be fixed).