Depends on the meaning of "sustained," but not all fusion startup concepts are aiming for steady-state operation; some are planned to be pulsed (Helion, Zap, probably others). The important thing is that they get more energy out than in, and enough more to justify the capex. (This is probably Q_scientific of somewhere between 10 and 30, depending on the specific concept and who you ask.)
commercial fusion as in the sense of the title is probably meant to mean "making profit", so significantly harder than just sustained fution, which will likely be obtained much earlier.
But it doesn't really matter, for now that's just an aspirational goal, not an imminent reality.