Show What They Know: Screencastify to Google Classroom

I was recently approached by a classroom teacher who was interested in using Google Slides but wanted students to record their voices as part of the presentation.  Immediately, I started going through the rolodex in my head of all the alternative solutions knowing full well that there isn't yet a way to embed audio into an individual slide in Google Presentation.

My options:

1. WeVideo - students add pics to the timeline and record their audio tracks.  
• PRO: Super collaborative and flexible as students can edit and rerecord without affecting other group members' recordings.
• CON: only one student from the group at a time can edit the master timeline.  Learning curve-- none of these students have used the product.
2. YouTube - students upload their audio as a video to their YouTube channel.  Students then embed the YouTube video (audio) into the Google Slide
• PRO: Students can record when and where they want.  Audio per slide!
• CON: Students need a YouTube channel.  Lots of guidance needed.  No great way to record/upload ONLY audio to YouTube...it would have to be webcam (with webcam blocked by a post-it?)
3. Screencastify - students record narration OVER the presentation and save it as a video file.
• PRO: Super easy to use.  Very little setup/training needed.  Easy to share as it integrates with Google Drive and Google Classroom.
• CON: All students need to be present and accounted for when recording takes place.  No way to rerecord a portion of the audio...all or nothing.

The teacher elected to go the third route since she wanted an easy solution while introducing the concept of screencasting.

The process:

1. Students collaborate on Google Presentation
2. Students activate Screencastify and record their audio over the presentation
3. Students submit their video to Google Classroom

Here's how they plan on doing so from start to finish:

Have an alternative solution?  Leave your ideas in the comments below!