The rollers press the seals together. But it’s not perfect. The seals are made from strips of mass loaded vinyl which is a good material, but it does not compress and therefore there are small gaps of 1/32” or so in various places across the seal, because the mating surfaces are not perfectly flush.It’s certainly clever but if it slides horizontally what compresses the join? Surely at some point it must move towards the hole in the wall? I can’t see how this happens. My thinking is that if a heavy door can glide past the opening easily, then the seal thickness and material is the only barrier to sound. I’ve probably just not been able to see how you‘ve sealed this in your mechanism
Still, it does work somewhat as is. I’m going to add some 1/4” neoprene foam tape to one side of the seal. That does compress and it should make a very good seal across those slightly uneven surfaces.
I hope that made some sense.