I dont use either of the encoders that are built into RDJ just for that purpose. Yes they lag or stall as I called it. I use stand alone ones. And DNAS has never been an issue, if you are setting up the programs correctly. I used it on my previous server hosts and no issues.
What version of the SHOUTcast DNAS are you running? Before this latest upgrade you are right, there was no problem with the built in RDJ encoder, or the one Marius built while waiting for the other to be upgraded to work on 1.7.7.
The new DNAS is not having a problem, but the encoder is not reporting listener numbers anymore, and there is nothing different in the RDJ setup prior to changing the DNAS version, so I am not sure how you can assert with such certainty that it is a setup problem with RDJ, and not the new version of DNAS.
If I switch back to the old executable of DNAS on the server, and change nothing in RDJ the stats work fine. So it clearly is a change in the new version of DNAS.