Depends on the exact type of DA/SA, I suppose. Some only have a decocker, no safety, and are not safe to carry cocked in SA, they are meant to be decocked when holstered.
Some do have a safety, one that does not decock when activated, those can be carried safely ‘cocked and locked’ if one chooses, which sort of renders the DA meaningless as it is effectively a SAO at that point.