I ran the A2L script descirbed here at the start of commissoning time this morning, and immediately after manually tuned P2L coefficents for the ETMs. I was able to improve the CHARD P to DARM coupling by about 25dB compared to the script's result. I tried tuning the ITM coefficents, but there wasn't much room to improve them.
I've updated the guardian values for ETMX, ETMY and ITMX (for a very small improvement on ITMX).
Compared to the script, my adjustments were fairly coarse. The script adjusted ETMX P2L from 3.1715 to 3.0875, while I then adjusted it to 3.35. For ETMY the script adjusted it from 4.682 to 4.7747, I adjusted it to 4.5. This resutls in the improvement shown in the attachment.
Editing to add: we relocked with these new P2L values, and the CHARD P to DARM coupling is still fairly low early in the lock (3rd attachment). The A2L coefficents aren't very sensitive to thermalization, which is good news.