By the way everyone, the absence of TRS jacks on the prototype was simply to cut down on turnaround time. I'm just going to solder some on manually for testing. That area supports either SMD TRS or the THT parts that I've been showing in the renderings. The plan is for the final devices to come with the THT threaded TRS jacks pre-installed by default unless you specify otherwise.
Also, on the soldermask color, my fabricator does that by default for all prototype orders, i.e. you can't specify another color. It's still an open question what the final color will be. We'll see if the red grows on me or not. I'm thinking matte black probably.