High Shinsoo aptitude is something that I'd expect to be associated with Wave Controllers and maybe Light Bearers more than anything, in fact high aptitude would probably be the reason for picking them for those positions, but it's something that every position uses to an extent. Shinsoo is used for reinforcement as well as forming rooms/bangs after all.

Keep in mind that a lot of people, even in the Wave Controller classes, were only learning to use Shinsoo for the first time; most were unable to even form one room/bang. It was only people like Laure who could do it already. Also keep in mind that Wave Controller was the smallest of the classes in terms of how many people were a part of it. Outside of people from the Ten Great Families I wouldn't expect anyone to be that proficient with Shinsoo yet, regardless of aptitude; not even Princesses or Irregulars, since the latter won't have any experience with Shinsoo at all.