It’s a common misconception that it’s ok to align your miter gauge fence to your blade. Their rational is usually that if the blade is misaligned, the miter gauge fence will be aligned with the misaligned blade — giving a square cut. This isn’t true as illustrated by this video. The miter track should be treated as the ‘master aligner’ — everything gets aligned to it — this includes the blade and miter gauge fence or table saw sled fences. If your blade is perfectly parallel with the miter slot, it’s usually safe (quick and dirty) to align from the blade but it’s not ideal.
