allocations are easy to avoid, just do not call anything but memmove and math.
and it is equally easy to "validate" by counting those "glitches per hour" if any.
one practical problem you may encounter - looks like you've already have all that massive amount of kernel code in C... yes, you can call that code from swift's input/render proc but ... is that that important?
found the link, interesting bits are around 0:38: https://devstreaming-cdn.apple.com/videos/wwdc/2016/507n0zrhzxdzmg20zcl/507/507_hd_delivering_an_exceptional_audio_experience.mp4
compare and contrast to 2015 video, around 0:49: Audio Unit Extensions - WWDC15 - Videos - Apple Developer