you asked:
"Is there a way to replay footage from what was captured on the drone to the secondary monitor that's connected to the live deck?"
The answer is yes, with a crystalsky connected to your live deck; pretty sure this can be done.
you may have been watching the wrong videos, since the cs unit has wifi and installing the autel explorer apk is the easier piece. not sure what you are referring to about maps and syncing up....to do what you are asking, you don't need to maps or "syncing" I don't believe. I have never reset my c.s. not even once. keep in mind, I am not suggesting you use the c.s. to fly your drone but simply attach it to your live deck as if it is a super monitor (wifi, runs apks, screen recording, video playback, hdmi in/out, battery, sd card slot, etc).
also, I might not have understood exactly what you are asking but if you are in the field and you launch your evo and fly for 15 minutes and capture 8 minutes of footage, you want to pause your drone and hover and before proceeding, you want to rewatch that 8 minutes of footage so you can make adjustments and fly a bit differently for the second half of your flight. is that correct?