--onlym4a or --onlyopus option?

[Mantve]

Hi, I've noticed that downloading a playlist sometimes results in some tracks being mp3 128kbps while others are m4a 160kbps, redownloading them sometimes drop additional m4a streams. I see that there is a --onlymp3 option to download mp3 streams and --only-original to get original streams but no way to set it to be strictly m4a or opus format.
Is there any way to easily control the download format beyond mp3 and original or does it depend just on soundcloud's mood?