New 'Vinyl Flat' flattener?

After flattening, is there any negative effect on the sonics of the album? In other words, is there detectable groove damage?

No negative effects that I can hear. The Band's Rock of Ages (2nd LP) is in the flattener now. I'll try and post some short video of before and after.

My first attempt at 5 hours on a severely warped (it was unplayable)new 180 gram LP did not work. It appeared it may have improved somewhat but still pretty warped. So now it's in for a second run....

Based on my understanding from conversation with Vinyl Flat, multiple rounds may be required for more warped records. Especially 180g I would expect.

My problem may be the Pouch. It has been plugged in for about 4 hours, and when I went by just a few minutes ago, I put my hand on it and it was cool. Fiddled with the connection a bit and it started warming up.
It was warm yesterday after I set it up initially, but I moved it to a preferred location and it might have gone cold. So another 4.5 hours as long as it remains working.