Hi Jim!
My question to the group is primarily about the splitboard layout - that is where most of my uncertainty and lack of experience is. In preivous testing, everything was on standard breadboard, and I didn't post the image of that setup. I used mechanical gauges, both with NIST certificates, air and hydraulic to check the performance of the Arduino setup - going from 1k thru 10k on the hydraulic and 40 PSI through 110 PSI on the air.
The symbol block for the Arduino in my schematic here, I pulled from the 'net - I wasn't sure whether to add the GND symbol near the bottom. There is a lead going from one of the GND pins on the Arduino, to the Terminal block, which is jumpered to the Meanwell V-. I hope this means I have created a Star GND?