Audio CD data has no such facility

To be absolutely scrupulously accurate, audio CDs have fewer such facilities -- they do use CSIRC, a cunning sort of splayed double Reed-Solomon. But wfaulk's point is still valid: if the CD is producing C2 errors (i.e. errors uncorrectable by CSIRC) then two players may well have different algorithms for filling in the gaps.

However a disc usually has to be visibly damaged to produce C2 errors. I'm thus pretty much as mystified as you about differences arising from (as your account seems to imply) any point on good CDs. The literature will have you believe it's all in the "jitter" -- the regularity or otherwise of the data clock on the fibre interface -- but it seems pretty likely that the DAC would reclock the data, so in your setup clock issues shouldn't arise, and anyway I'm not convinced that jitter is necessarily perceptible.

Peter