I'd like to resurface an already somewhat level but tarnished concrete floor with a self-leveling cement-based compound and to raise the floor level as little as possible; I've found compounds like Mira 6700 where the manufacturer specified layer thickness starts at 1 mm, so presumably the compound should be able to level itself even as a thin layer. The question is, what would be the downsides of using a thin layer? I would properly prime the floor and use a concrete densifier after, and the floors would have minimal traffic.
The only drawback I can think of is that self-leveling products don't tend to feather themselves to a knife edge. They tend to leave an edge similar to what you'd see with a puddle of water on a glass table, with a bead of approximately 1/8 inch thick. So if your layer doesn't cover the entire floor you'll need to deal with that by tooling at partial cure, or by skimming with another product such as a vinyl concrete patch. Otherwise I have no concerns.
Be aware that most such products are not intended as a finished floor. They're somewhat soft and can gouge and wear easily.