Also, I discovered a super cool way to share these projects to Seesaw. Instead of saving finished projects to the camera roll of your iPad (and taking up a bunch of space!), use the clipboard tool. Teach students to select the clipboard and then "share".
It will process the video, then students will select "done" and open Seesaw. Instead of uploading from the camera roll, they'll choose "link".
The link will automatically show up, students don't have to type anything! Wahoo! They'll just click the checkmark and post as usual. Super cool and easy!