Yes. Soft combining (in systems designed for it) isn't even done on bits, it's done on the actual analog (well, a digitised version of the analog value, sometimes termed a "log likelihood ratio") values of the signal in question -- before any quantisation happens.

This isn't to say that you can't apply the techniques here (where stuff obviously gets quantised unless you can find a way to get the raw signal from the photodiodes), but you need access to bits with the least amount of error-correction involved (or find a way to infer what the statistics of the original raw bits are from what the decoding machinery outputs).