Great OST! I think Duality is one of my favorite tracks on this jam. Also love 2nd a lot. Very pleased with dynamic development in 1st and last tracks. Every tracks feels different and provides its own beautiful soundscape, but the whole thing is coherent.
In the first track, after dynamic rise, piano sounds a bit too biting under compressor. Maybe it's intentional, but it kinda scratched the ear.
Also it seemed to me that lead in the 3rd track is a bit too loud.
Nice job overall!