You got it. Those bolt PIDs will list all 96 of the battery cell voltages.
I use a permanent OBD2 tool such as the OBDLink LX in the Spark EV to give me realtime data and share that with navigation apps like A Better Route Planner to read my state of charge and power. I went with OBDLink because it's a popular OBD2 tool for EVs, doesn't allow random hackers to mess with the car systems and possibly do something malicious after injecting commands, and the tool has a low standby power consumption.
I think TorquePro is the app of choice to go with, considering how it is the most widely referenced and supported online. Many will work, but I run TorquePro for just about everything along with OBDLink's own app as a backup for whatever reason.
Yes the VCX Nano is one of best diagnostic tools to take full control over your GM property. It does require some setup, but most people who appreciate this level of control don't mind installing a program and following a guide.