I used the IM4 pico to center the beam on the QPD with 2W into the mode cleaner this morning (screenshot attached). We had some shifts of input alignment during the vent and difficulty recovering (see 76359 76291). Now our range is 165 and locking seems reliable, so we are resetting the IM4 QPD to zero here so that we can use this as a reference in the future. LLO tells us that they realign IM3 to this QPD every few months.
This increased the sum of IM4. Since this sum is used to normalize our PRG channel, this will need a recalibration.