Powering the 12V rail additionally resulted in my programmer being able to see and program the chip. Oh crap, I figured I screwed up royally again, but a quick look at the schematic revealed I allocated one of the programming pins double duty with driving an h-bridge and since I only supplied 5V and not the 12V coil drive rail I suspected the pin was being logged down. I was pretty nervous firing v2.0 up for the first time when I tried to flash the firmware and my pickit couldn't even see the PIC. In terms of the communication/interrupt/higher level architecture nothing else really had to change. The rest of the lower level code to handle all the extra outputs though had to contend with independently driving each segment, but luckily I decided to wire things such that segments were in logical order so a simple port write can easily correctly set an entire digit in one fell swoop (with a small exception of hardware rx/tx pins which required one of the segment G pins to be tacked onto another port). Luckily, basic code-wise nothing really changed as they both have the same core, just the 887 has a ton more I/O.
I was using the diminutive narrow smd PIC16F886 package in v1.0, but for 2.0 I had to upgrade to the PIC16F887. So this brings me the the second notable upgrade. The only casualty was the nice pretty routing of the board that I was so proud of in v1.0 is now an absolute mess to squeeze the 14 soic chips in along with a larger micro for the necessary extra I/O.
After all the L9110S chips I got from ebay were only about $8 with free shipping for 50 chips which ends up to comfortably make three modules with a few chips to spare. So after the failure that was prototype 1, I've decided to dispense with trying to be clever and save pins/silicon and just throw an independently controllable h-bridge chip at each of the 14 segments (2 digits per module).