I played with the DD handoff during the day. The DRM dark port was flickering like a candle flame in Dracula's castle. The demod offsets for the handoff signals looked fine. After MICH handoff, the MICH_CTRL started to get unstable at some low frequency, maybe 3 Hz (I didn't measure). So I increased the MICH gain from 0.1 to 0.17 and it settled down. PRC and SRC went fine. Then the DD_handoff script raised the MICH gain to 0.7, and an instability started to grow in MICH_CTRL (at some higher frequency). I decreased the MICH gain from 0.7 to 0.5, and it settled down and stayed stable.