Got an airtripper style load cell sensor set up - Right now, only with an HX711 as the amplifier (instead of an instrumental amplifier feeding directly into the AVR). Should soon have it set up and reading filament pressures. Ideally, looking into applying strain gauges to our existing parts to keep reading on strain present in the system.
These things are amazingly sensitive, and amazingly quick (instantaneous) to react. Hoping to develop it all much further, allowing us to implement auto-temperature for filament, auto bed mapping, filament slip detection, collision detection, and many other advanced features that FDM printers could have used for a long while. Another benefit…all of this can be done cheaply. Load cells are like $10, and the amplifiers $5 or so.