It was reported that such correlation may not exist. Instead, the subsurface damage  correlates strongly with the  laser damage threshold:
Byungil Cho, Andy Lyu, Mark Feldman
Laser induced damage resistance of 266 nm AR coatings
in Proceedings of SPIE – The International Society for Optical Engineering · November 2013

Due to its high density, IBS optical coating does not absorb atmospheric moisture, so that its reflection spectra is not changed when exposed to the air after deposition in vacuum.

Chemical Mechanical Polishing  (CMP) 
is a machine- defined,  precisely controlled  deterministic process: once a high polishing quality is achieved , it can be routinely repeated. That is not a case for conventional 
manual polishing,  which is a hand-defined, non-deterministic process.

When using appropriate polishing materials and methods, a sub-nanometer surface roughness can be achieved even with abrasive particle size as large as 1 micron.This allows to skip intermediate steps between rough lapping and finish polishing thus reducing the fabrication costs.

At UVIR Crystals we developed a process of surface material removal that allows to sputter-off the so called “polishing redeposit” which contributes to optical absorption and laser induced damage.The unique aspect is that the rms surface roughness decreases in course of such ion beam sputtering.

LBO is moderately sensitive to moisture. Therefore, a main rule of handling LBO crystals is to avoid their contact with humid atmosphere
at RH> 50%. If such contact happened, then dry out  the crystals at 60-80C for  3-2 hours and place them in an airtight  container  with desiccant.

ethyl acetate is the best choice because  it does not produce as much cooling as acetone during cleaning.
Cooling  may cause the damage of  LBO due to its high   thermal expansion coefficients