No idea where you even get the DLNA reference, as SoX is not related to such technologies.
Hi Hendrik,
The DLNA reference is because your current audio transcoder does not support seek to a time position ahead of the current output buffer size. So you have to wait until the transcoder run has finished before your HTTP server could support a seek on that part of the buffer file. By contrast, if you used the SoX transcoder instead of the MC transcoder you can simply call SoX with the -T time offset switch, to start a transcoder run at a specific time offset from the start of the track. Then you can pipe the output of SoX straight into your HTTP server output stream, and therefore support seek properly.
Believe me, if you think I am an idiot, I can assure you that I am not. I know very well how SoX works, and I have used it myself in my own Whitebear UPnP Media Server. If you want help on this, I can advise. I have been pushing for JRiver to fix this issue for years. SoX finally gives you the tools to do it properly, and rather easily..