I've decided on a dual-screen setup of a Sharp 2.7" Memory-in-Pixel display for the active work and a Waveshare 4.2" epaper display for output/reference. Both of these have active development and libraries/drivers for the hardware I'm using.

I feel bad for buying more new tech instead of recycling like I would have with the hantronix display (which actually is a powertip display?) but I can still use that for other projects down the line. It will be fun to hack on, but it ultimately doesn't fit the goal of this project as being an actively usable field tool.

The added bonus is that both of these displays together will draw even less power than the powertronix-whatever-it-is display.