If we just consider this is a factor of 11 between green and IR filter cavity locking accuracy as pointed in entry 760 figure 6, we could estimate the IR locking accuracy of the filter cavity. (in green locking case)

As reported in entry 1486 and entry 1513, we have green filter cavity locking accuracy of ~4Hz. This is corresponding to 4e-12m.

Then by considering the factor 11(because of cavity pole of green and IR is different), the locking accuracy of IR should be 0.36e-12m. In this case, it meets the requirement of filter cavity length fluctuation.

But we still need to confirm the measurement of entry 1486and 1513.