I suspect this is more of a collaborative scientific effort rather than a commercial enterprise. However, they do mention in a tweet that they are supported with funding from the Flatiron Institute (Simons Foundation):
Thanks. Interpolating between map projections that have the same clip region is relatively straightforward. When projecting geometries from the surface of a sphere to a 2D plane, you're always going to have a discontinuity somewhere on the sphere, i.e. the clip region. The projections supported so far all have the same discontinuity along the antimeridian (the meridian at longitude ±180°).
Extending the interpolation to work for projections with different clip regions should be feasible but there are several ways to interpolate between arbitrary shapes in 2D, so I'd have to give it some thought.
Another way to transition between "polyhedral" projections like the Dymaxion map and the Waterman butterfly is to fold and unfold the maps in 3D to and from a closed polyhedral globe.
I had to limit the number of airports displayed for performance reasons. I filtered the airport data so that only those airports with scheduled services and which are denoted "large" or "medium" are included (according to OurAirports), bringing the number down to 2,980.
Suppose that'll explain why there are at least three airports included in Ireland that have no scheduled services at all: the data's from nearly a decade ago
It's probably to avoid dead-code elimination, which would defeat the purpose of the benchmark. The rust benchmarks use test::black_box [0], which does the same thing, so there's no unfair advantage there.
