What you should do before moving off is effective observation, whether that means the 6 point check or a lesser, minimal version doesn’t matter provided you know it’s safe before moving off.
Effective observation is about making the appropriate visual checks depending on the current situation. Where you may want to consider a full, comprehensive all-round observation such as the 6 point check is if you’re moving off from a busy street where pedestrians may cross the road in front or behind you. Whereas if you’re moving off on a typical residential street that’s relatively quiet, the perfectly adequate moving off checks of looking out the front, the interior mirror, right mirror, right-side blind spot are likely just fine.