Yeah, it's 100% sw stabilization. The mount that they are hoping you'll buy so they get a commission does have silicon/rubber contacts which would make it a bit better than a completely rigid mount.
It's unclear to me if their stabilization is any better/different than what I can already get through my Pixel and Google. Need a subscription to get the good stabilization, remove watermark, and the ability to record in background(on Android at least).