Hi,
I have good knowledge of RTMP and linux. I already have a solution that can split RTMP streams into multiple files so it should speed things up. I think the easiest solution for this is to rely on ffmpeg to do the transcoding.
I will need a bit more information about your setup first though. Like, what kind of server do you want to send the HLS stream? Where are the RTMP streams coming from? Also I'm not sure what you mean by "6 segments per playlist". Does it mean that you have 6 possible streams? Which linux distribution do you use?
I hope that my questions make sense,
Eric