Bottom bracket spin test. Say nothing.

They actually are tricky to really make assumptions about the real friction.
As we do not know how the grease inside behaves under load, when getting warmer, and so forth.

What we can certainly say though, is that this frames’ bottom bracket shell has been properly faced to have clean, smooth and perpendicular surfaces for the bearing cups to snug up against, allowing the spindle to experience the least possible friction from misalignment.
So, these “race” bearings, with oil instead of grease, no- contact seals and being of the best quality available, show us certainly this, at least.