You are provided with the option to exclude individual fixture results from the Standings table. This checkbox will be defaulted to on/off based on the settings populated in the phase settings for each grade.
To disable/enable the results from a fixture to generate points for the Standings table simply check/uncheck the Show in Ladder box next to each fixture.
Note: If a playoff phase is linked to an earlier phase that has fixtures with Show in Ladder unchecked, the unchecked fixtures will not need to be scored for the playoff teams to be populated.