Since an "arbitrary piano" is tuned by turning screws, like simpler string instruments, the only pitches that it cannot be tuned to are those that fall outside the range of each string. Departing from the usual inharmonically tempered 12-EDO tuning would just sound strange, possibly outside some piano tuner's professional comfort zone.

https://www.modartt.com/pianoteq_overview :) Very high quality and affordable software modeled piano. It is rather easy to tune via Scala KBD formatted files.