Why does PTX compilation with the driver not support a -dscm option?

The recently-introduced PTX compiler API allows specifying both a default load caching mode and a default store caching mode, with options -dlcm and -dscm respectively.

However, the CUJIT_optionenum only seems to offer CU_JIT_CACHE_MODE, which corresponds to dlcm (reading) only, not for writing.

Why is that?