The autolocker was struggling to lock the IMC. I disabled the autolocker and locked the IMC manually. It seems happy right now.
With PMC trans at 0.717 counts, the IMC trans sum is ~15230.
The MC autolocker hasn't been so snappy recently, and has been especially fussy today. Previously, the mcup script was triggered immediately once the transmission was above a certain threshold. However, this could waste time if it was just an errant flash. Hence, I've added a 0.5 second delay and a second threshold check before mcup is triggered.
After breaking the lock 5ish times, it does seem to come back quicker.