Would selecting a Goal of 1W increase in 20min Power over 3 months give the basically the same outcome as selecting Continuous and Maintain? I assume it would but I have been known to be wrong about things on numerous occasions.
Or what is the best choice for the off season?
For a 1-watt gain, picking that specific goal works fine. For off-season, I’d use Continuous with Maintain to hold fitness without extra strain.