Support for MultiChannel Audio Files

Normally when I finish a video project I usually create a full render containing the stereo mix track, then a number of separate WAV files, one by soloing the dialog submix, then soloing the atmos, the spot effects, and music etc, for however many submixes I want to keep. As Quicktime supports multichannel audio, and so does Premiere Pro, it seems more appropriate to create a multichannel master on the sequence so I would be left with a single file containing the video and multi channels of audio, should I ever want to remix the audio in future.