my comments on Jim Martin On Stratification:
contextual strata are metaredundant on the redundant relation between discourse semantics and lexicogrammar... hence relating clause meanings directly to context skips a layer of metaredundancy
(1) clause meanings
The meanings of clauses are semantic not lexicogrammatical. Hence relating clause meanings directly to context does not skip a stratum.
(2) layer of metaredundancy
Strata are not layers of metaredundancy. Metaredundancy is a redundancy on a redundancy. Semantics is metaredundant on the redundant relation between lexicogrammar and phonology. Semantics, lexicogrammar and phonology are not "layers of metaredundancy".