Great review. I was an early owner of this sub and your observations
match my own. I didn't have the guts to take mine apart though for fear of bending something up
One suggestion: you may want to note the model number on the Tabbed Measurement Data as "PB12-NSD (2011)" or similar as SVS has been updating their models every couple years without much in the way of model number changes. People logging in to view your data may confuse it with the previous model.
Keep up the stellar work.