Hi!
So, I have been having some fun with microtonality using the A4, by means of filter keytracking, poly, etc.
This is a recording of some tests: https://www.dropbox.com/s/vbimvv48y1bqinb/Microtonal_Experimentation_on_Elektron_A4_mk1.wav?dl=0 (WAV download).
Not a song, no nothing. Just raw experimentation using my A4.
Cool, care to explain a bit more about microtonality and what you actually did?
Hi!
Sure thing.
It’s quite simple. Take the basis of turning LEV->0 for both OSC1 and OSC2. Then move to Filters.
We will use filter self-resonance to generate audio. Set Filter1 FREQ to a middle frequency. Set Filter 2 mode to peak. Leave it at RES=0. Crank up Filter1 RES until it starts generating sound (of course, you can set some TRIGs on C2/C3/C4 etc to have an idea of note range).
Now, If you set TRK to +32 (or -32, depending) you will have Octave-width key tracking. The filter frequency will change accordingly. Different notes will sound. But what happens if you set lower values for TRK? Instead of an octave in 12 semitones, do we have 24 “semitones”? not really, because we do not have intermediate keys. So the spread goes over more keys. To get a full octave, now you have two move up or down two full octaves. (C2->C4, for instance). But now you have less-than-semitones per note! You can experiment with micro-tonality 
Of course, this is an oversimplified explanation with lots of mistakes, but I think it transfers the concept easily.
Then you keep playing with the other filter, and by setting different TRK values you can even create microtonal chords, etc. Set up some performance macros to adapt frequencies and tracking values.
Play with LFOs and AMP. Add some DEP1/DEP2 and tweak ENV parameters.
Enjoy!