Hello, as I know, OCCT STP reader do not support at the moment semantical presentation of surface texture (also known as surface finish) symbols define the lay (direction), roughness and waviness of a surface.
Reading and exporting pre-tesellated representation must work. Extending of semantic presentation is one of the our target for 8.0.
If that functionality is require for your project, you can request feature development (Bug Corrections And Improvements - OCCT3D).
Best regards, Commenter-1.