Copying and pasting your interactions will save you a lot of time. There are two options to reuse your interactions:
Copy interactions within the same video
Step 1. Click on the interaction with your right cursor button and select Copy
Step 2. After the page is refreshed the copied interaction appears below the original one
Step 3. You change the timing or design of the copied interaction just like any other
Copy interactions from another video (reuse interactions)
Step 1. Click on Reuse interactions on the top right
Step 2. Select the video of your choice
Step 3. Select the interactions you'd like to copy
Step 4. Click on 'Import'
Step 5. After the page is refreshed the imported interactions will appear in the timeline