I'm not convinced by this. I can't think of any technical reason why they would render the ABBAtars CGI live every night, when the concerts are all identical. It would be an incredibly inefficient (and frankly unreliable) way of doing things, when you can just render each song as a pre-made video clip and play it out.
Given how long it takes to render off one frame of a Pixar movie, I'd go as far to say it's unlikely to be feasible to render the ABBAtars CGI live every night.
Perhaps the LED video wall needs to cool down? But even that would be surprising, given that Voyage is no longer than any other concert or TV show making extensive use of huge video walls.
It is 1 screen used throughout the whole show. The whole show is effectively a pre-made video clip. Even during DYMK, the screen is still on to give the illusion that the stage goes further back than it does.
Ludvig and Svana have confirmed that it doesn’t need to cool down. That was just a fan theory early on in the show.