Still buffer starts low, but, M now goes much lower, 0.0001 it looks like it tries hard to push start buffer to center, i hope it's that. Testing with 11ms buffer (1block+headroom) and default block size, starts with stutter 2-3 seconds and continues normally and syncs ok. Buffer fill is now much closer to 50% around 52% (with 400ms buffersize), seems ok. On lower buffersizes is too much jumpy to read.
edit: Noticed that M slowly goes to 1.0000 stays some time and then fastly goes back to 0.95000 stays there bit long time and agian slowly to 1.0000. -66ms latency, but it happens in any latency.
So, is this the same as before? I think I have just solved the startup behavior, will run another build tonight.
M indeed goes lower and pushes harder to the center, which means (as I wrote before) that you can probably use smaller "Relative adjust" values, which is a good thing! Before the correction wasn't symmetrical (it could push down faster than it could push up; that's now no longer the case.
In normal situations (where the M value is close to 1) it doesn't make any difference, but for extremely small buffer sizes it definitely does.
So, I'm starting the BETA015 build now; it should automatically upload to the server about 5 hours from now (around 4:00 UTC) if anyone wants to test it before I've had a chance to post it here.