Why flake is forgiving
The randomness of a chip broadcast means there is no pattern to align and no uniform field for a patch to contrast against. As long as the same blend is used, a repaired square metre becomes indistinguishable within the surrounding floor. Over a twenty-year life this matters more than most people weigh at the point of choosing a finish.
Why solid and metallic are not
On a uniform colour, any difference in batch, age or gloss shows permanently against the surrounding field. On metallic, the pattern is a one-off event that cannot be reproduced. The practical approach for both is to re-work a full section bounded by a saw-cut or a natural edge, so the transition reads as deliberate.
Re-coating versus repairing
Widespread dullness or traffic-lane wear is not damage, it is the topcoat doing its job. That calls for a re-coat rather than a repair: light abrasion across the whole floor, clean, two fresh coats. It is a one-day job and it does not disturb the decorative layer underneath.
When it is not worth repairing
If the coating is lifting rather than chipped, clean concrete visible on the back of the flakes, or domed bubbles. The problem is adhesion or moisture and it will keep spreading. Patching that buys months. The floor comes off, the cause gets addressed, and it goes back down properly.
Want this answered for your slab?
Free site visit with a moisture reading, then a written fixed price. Across the BC Interior.