Today I measured the amount of space available on the table for the new (4-fold) C.Ri.Me. setup. It's 1050 x 1220 mm, with the table hole in it.
So I updated the optical layout to fit into this space, and optimized the telescope to have a beam spot on the QPD of the order of 350 um. The average lever arm length is 1.5 m, so the optical gain will be about 7000 /rad.