I must admit that there is a limit to how impressed I can be regarding machined metal tubes that you plonk bearings in.
His designs are not revolutionary or complicated - but they are good. His unique selling point is that he appears to use (or is?) a manufacturer that is accustomed to the higher tollerances required by aerospace or similar industries - so yeah the variations in manufacture are minimal and accuracy to drawings excellent - might be a little overkill but there is obviously a market for it so good luck to him.
I’m also of the view that the effect of friction in the bottom bracket itself is not huge in the grand scheme of things. My winter bike ended up with two completely seazed up bearings after 6 years of neglect - the crank was just rotating within the ID of the bearing and there were visible steps where material had worn away from the spindle - and that was still only losing me a handful of watts. I’d be very surprised if the difference between the best and worst fully functioning BBs available was more than 0.5-1w.