It means that regular people have regular Shinsoo, and special people have special Shinsoo with special qualities. My interpretation of this reads that: people with cool Shinsoo can host a Firefish and not be consumed by its heat; people with a hot Shinsoo can reach a temperature so High that Shinsoo itself gets burned; high tension Shinsoo can be shaped like an orb; and so on. Indeed, people with a low tension are unsuited for creating Orb shaped Shinsoo, Just like cool Shinsoo likely can't reach the "True Fire" temperature, Just like a small person can't be a Defender.
Imho, Miseng's Shinsoo has what Kallavan described few chapters ago as "explosion Power". Her Shinsoo bursts suddenly. Kallavan mentions this because his explosion Power is higher than Bam's, but Bam's infinite flow eventually overwhelms his explosion, by his description. I think this might be a requisite for the misterious Dansulsa position, that exerts sudden extreme pressure on one point, the one that Kurudan used remotely to squash Ren on 2F.
@kkck : re-reading Edwan's line, I get the feeling Qualities are like 'width', 'volume', 'density', or 'hardness' that materials have, bit the Shinsoo version of them. So "Reinforcement" or "Ice" doesn't seem like qualities. AA's Shinsoo is likely cool and hard, which are qualities, and the end result is an icelike Shinsoo. Figuring out one's Shinsoo qualities results in better uses of that Shinsoo, not necessarily 'different elements'. If Miseng has a High explosion Shinsoo, her applying It to reinforcement results in sudden, High powered moves, or maybe like Kallavan's: AoE dmg Shinsoo atks. Each Shinsoo quality combination results in a different effect, and may bê used in several ways, such as a rod can be used as a walking stick or as a lever. We know Bangs have numbers, size, density, and now we know Shinsoo also have several statuses.