Who here that does flowbench testing w/ large-capacity flowbenches tests at HIGHER than 28" H2O, even though 28" is the standard?

I've read some stuff on SpeedTalk, et al, where some well-known head porters recommend testing at 36" (or higher, if your bench can pull it) because certain flow issues don't show up at lower test depressions.

As I'm considering a flowbench upgrade, part of what I'm taking into account is flow capabilities at both 28" and 36" for just this reason. Therefore, I'd be interested in hearing about examples of testing at higher than 28" revealed issues that were able to be resolved from refinement / revision to the port design.

Thanks,
Brad