Merging multiple tracks in 1 stream

I’m sorry if I come across as a total noob, but is there a way to add multiple audio tracks to a single stream and send it through some transport like mediasoup?

I want to build a multiple audio recording feature in a conference calling app. I’m using mediasoup for SFU and FFmpeg for recording individual streams on the server end.

However, this solution seems to require a lot of port management and other computational overhead.
I was thinking, can the tracks from other producers be somehow “merged” together to form a single stream which can be produced from a single “SuperUser” who records the call.

Is it possible to implement such a system?