I've had a quick look at the duty cycle during owls for O3a. A couple of quick numbers:

Of 176 total owl shifts, there were 96 shifts the IFO was locked when the owl shift started and stayed locked the entire time.

There were 7 shifts where the IFO never got to NLN.

The duty cycle for all O3a owl shifts was 84%, or: we were in some state other than NLN for 16% of the time.

Attached plot is the distribution for the amount of time the IFO was not in nln. The X bins are the number of minutes (with 30 minute bins) the IFO wasn't locked, the Y axis is the number shifts for each bin (i.e if the ifo was out of nln for 130 minutes, that shift gets counted as 1 instance in the 120-150 minute bin). I'll point out the tallest spike by far is the one at 0,  where the IFO was locked the entire shift. 

Not too sure what else to make of this, but the lump around 150 minutes kind of lines up with our normal time required to relock, indicating to me that mostly we lost lock once, then had a normal time relocking. Probably, most of the bins below 100 and above zero are from locklosses at the end of a shift, or a reacquisition that was started before the owl shift.