The interferometer was stably locked at 25W (23.3W measured) for the last 4h, and all violin modes are damped to nothing (actually better than in O1).

Here is what I think we should do next:

- The one attempt going to higher power was unlocked by the Izumi-Ballmer instability at the main pendulum frequency. Time to mitigate that - ISS 3rd loop?

- The quick attempt in thermal tuning that Peter and I did suggested that we had too much central heating. We should nail down the optimal thermal tuning.

- Also, time to switch OMC_PD whitening and impedance back to low-noise.