Chlorines can cause damage and acids within the oil during the combustion process. In a gear application where temps are lower, CP's may not be as critical except for possible seal swelling or drying of the rubber component. Boron has come a long ways over the years, newer nano-boron seems to be a good friction reducer if not used in large amounts.
We found in the lab newer moly's are coming to the market and working great, seems time and technology has come a long ways with Moly options. We did some current testing with a moly additive for an engine building group in California and saw some great results in wear metal debris as well as bearing scaring. When added to their engine oil and doing a ASTM D3233 4-ball wear test, the numbers were pretty impressive.
We did have SGS Labs run a chlorine test on the X1R, it did come back at 140,000ppm utilizing the HL-1168 test method.