https://aeroxplorer.com/articles/meet-the-startup-building-the-plane-everyone-else-said-was-impossible.php
Article mostly just repeats the claims of the manufacturer, but it's followed by this interesting comment, apparently by a retired professor acoustics:

"I have considered whether the Otto Phantom 3500 might have extended laminar flow, as claimed in this article. In the article I published in Journal of Fluid Mechanics, Vol. 144, pp. 79-101 (1984) shows that the transition Reynolds number for an axisymmetric body that is perfectly designed and built for extended laminar flow is 4.5x10**6. The fuselage of the Phantom 3500 is similar to the body I tested in that article. Presuming operation of the aircraft is 500 mph (534 fps) at 5,000 feet, where the air temp is 41 degrees F, the kinematic viscosity of that air would be 2.3x10**-4 (feet**2/sec). The length of laminar flow over the Phantom 3500 fuselage would thus be (transition Reynolds number)x(kinematic viscosity)/(aircraft speed) = 19 feet. I am impressed!!!!"