The simplest solution is converting the detune values to an JS array and use this with Message.setFineDetune(). If you have the same detune values for each octave, use Message.getNoteNumber() % 12 to stay within the array limits
I see. I hope Player will be ready some day, it can be a real alternative to Kontakt.
That looks like a lot of work, if you are the only developer of Hise (why don't more people contribute to the project?)
Meanwhile, is it possible to make a sample player using Hise, like Sforzando?