Since we have access and I was in-chamber anyways, in:

• BSC1, I swapped the witness plate directly that was under the ITMy with a fresh one - see T1300874 for eventual analysis of the removed wafer

(2 more plus 2 1" optic samples were left alone for posterity)

• BSC2, I swapped the witness plate that was directly under the BS with a fresh one - see T1300875 for eventual analysis of the removed wafer

(1 more plus 1 1" optic sample were left alone for posterity)

• BSC3, we added a fresh witness plate (none previously in this newly populated chamber).