TJWillis:
I havent had a resync for months forced by DLM and have asked Snap why but they don't want to know and feed me the same bullsh-t everytime I ring. So maybe this will get the ball rolling with resyncs.
Why would you want resyncs on DLM1??? You're on DLM1 and I'd say you're very much borderline for 17a, so you've probably got as good a connection as you're going to get. DLM probably can't do anything to make your line better.
Looks like a nice SNR tweak though and with that error rate it looks like you still have some headroom to play with.
EDIT: Ah I see your question about sync rate varying with DLM resyncs now. While yes it MAY vary, that variation is random and depends on the line conditions at the time of resync. If you're on already on DLM1, I DON'T think it will initiate DLM resyncs to try and increase your sync. It will only resync to drop you down a level (which you don't want) or put you onto 17a (And I'd say your attenuation is too high for this)