Vinyl Junkies …

I've got a vinyl flat flattening system, with the heated pouch. I've used it with very gentle heat over a few cycles and managed to reduce warps less pronounced that the warp in that video.

Also had good results just leaving the disk in for a few months.

I don't use it often but I had a few high value items from the 90's that I wanted to try it on so bought it second hand.

In summary I think it can work but it's also quite easy to overdo it with the heat.

If it is new see if you can get it replaced. I have had two recently that were badly warped and they were replaced no quibbles.