Congrats on the awesome project. In case you haven’t come across it ACAT [1] might be of interest, especially if word rate becomes a limiting factor in communication for you dad, or if he’s interested in using a computer. ACAT is highly flexible around how it accepts inputs. To that end, you might be able to take what you’ve done and open it up to a broader audience by writing an extension that turns the iPhone with force touch into an input sensor, with or without the use of Morse.

[1] https://github.com/intel/acat