Holy cow that was a thorough review. Great job.
Only thing I can add is I have the flip diopter and how I use the tripod.
I like my rig as close to neutral as possible. However, that doesn't work well when using the tripod. I place a 2-3 lb soft weight on the top of the housing for tripod shots. That held it steady for macro even in the surge. Best part of the tripod is the foldable legs which lets you setup/down very quickly.
The internal flip diopter worked great for me. My eyes are not as critical as Drew's, so the single element diopter clarity was fine. The best part of this option is the diopter is on it's own flip arm. That allowed me to shoot wide/standard angle with the filter in, no lights and then go to macro, no filter, lights on and flip in the diopter in seconds.