Check with each school for their policy. It will be on their admissions website. Sometimes it’s a bit hard to find (looking at you MIT).
D22 is completing 12 applications. Four require official reports from College Board with the application. The other eight accept self-reported scores and require an official report only if she enrolls, next May.
Yes, you can send scores, and other material, before your application is submitted. Schools will match everything up as different parts are received.