Quarter tones and tablature

Hello,
Quarter tone support on playback based on the custom key signature would be nice.
I understand quarter tones are a complex subject that can vary depending on the tradition. What about a user-defined tuning of each note upon creation of a custom key signature? (e.g. I create a key signature with a flat on B/si and a "koron" (half flat in the Persian system) on E/mi. I can then enter custom tuning for each note (either after a prompt, or after clicking a button...). So I choose to tune all E/mi notes to -50 cents.)

Additionally,
Tablature could be made to support quarter tone instruments by allowing the user to define the notes each fret makes. (e.g. A table with numbers representing the frets, and the user can attribute a note and tuning to each. This would allow linked tablature to work for instruments that have frets for the quarter tones.)