The Online Safety Act provides for Ofcom to develop its own codes of practice and guidelines based on the provisions of the act and public consultation (including with the platforms). It has an enormous amount of leeway in deciding how to implement the Act.

Ofcom has operational independence. Neither its investigations nor its enforcement actions are directly controlled by the Government. The Government does approve Codes of Practice but if it doesn't approve, it can only request modifications. It's still up to Ofcom to decide how to interpret and implement. Secretary of State interventions are, by convention, rare and subject to Parliamentary scrutiny.