Yes! You can and should add your sub-contractors to Siteaware. This will allow them to get notified as soon as their trade's elements have been verified so they can begin correcting observations or installing any missing elements as required. They can then document their corrections and close their observations for GC Review saving you the time that would otherwise be required to directly manage the deviation and its fix.
For more information on how to add users to the platform and what trade users can and cannot do, please see the following articles: