Tvheadend

I do this (transcode MP2 radio streams from DVB to AAC for Sonos in TVHeadend) without problems. I'm using 4.3-1857 so a slightly older build, but none of the later commits should have changed the behaviour of this.

Which radio stations/satellites are you trying to play on your Sonos?

I have a "Sonos" stream profile set up in TVHeadend with container as "Raw Audio Stream". This is set to use an audio profile which is set-up as:

Codec: AAC
Limit Audio tracks: 1
Bitrate: 256
Other settings (Sample Format, rate, channel layout): auto

I then add the streams to my Sonos radio stations in the format http://<tvh_ip>:9981/play/ticket/stream/service/<uuid>?profile=sonos

As it's local network, I don't use any authentication for this (it uses the default user with no password which is allowed on my local network for streaming).

These streams report as 32-bit in VLC for me too, but they work fine on the Sonos.