OK, think I know what happened, and I don't think we were charging by moonlight after all.
Turns out the Rogue will not make a log entry when entering REST if the accumulated Ah are less than 1 Ah. This is to stop multiple spurious entries in the morning and evening. Now I just got the whole show working late afternoon yesterday, and I also shut it down and restarted it at least once IIRC, so I suspect that the Ah were less than 1 Ah at REST last evening. So no log entry would have been made.
Also, this morning when I tested the log function and got a good entry, the time spent in ABSORB and FLOAT modes is recorded. About 1.5hr total which is about right if it had awakened from REST earlier in the morn.
Anyway, I'll double check tonight, but pretty sure that's it. It'll take a while to learn all the ins and outs of this thing ...