Over the holidays I was able to finally nail down some requirements. The design has been simplified a lot, eliminating a whole host of hardware that wasn't going to be used anyways. As a result the schematic is largely finalized and the board design basically done, now in just 5cm x 5cm. I've started adapting the software to all of the latest changes and once it's running again in prototype it will be time to order the v1 boards.
I've made a fair bit of progress on both the hardware design and the software for the microcontroller. However there are still some requirements that that aren't sorted out that are preventing me from finalizing the design. I'm not quite ready to give up on this project yet but it's definitely moving slowly at the moment.