I think the video in post #6 is dead-on; If you can get the same lube for 5% the unit cost, you can change the lube much more often, and that will prolong the gearbox life, because this lube is not filtered while in operation. This is not a case of cost delta 2000% between $0.05 and $1, but over $30 for a tiny amount of oil, so frequent changes at that price can add up to a lot.

The metals content under analysis is, I think, typical for the first oil change after the factory lube, because the gears are wearing-in, as noted in the report. This is why I like to rush initial lube changes on cars from the factory, for example, not waiting 50,000 miles to do transmission lube change, unless the drain plug has a magnet on it for pulling iron and steel particles out of solution.

Pinion uses "straight" 75W lube. This is fine, because they don't need high temperature performance. But a 75W-90, designed for high temp as well, will do no harm, and notably, an auto gear lube is designed for both rolling and sliding contact on gears, and for ball and roller bearings, exactly the same as in a Pinion gearbox. Synthetic lubes tend to outperform conventional lubes, however, decades in the past, some synthetics would destroy some rubber seals and plastic parts. I think this is less prevalent these days, but always good to know. One person on the forum said they found a Sturmey-Archer Correction: Shimano Alfine 11 filled with automatic transmission fluid, which swelled a plastic seal or nut to where it disengaged from the axle threads.

Some of the other elements in the analysis, such as calcium, may be from the oil used, not coming from any of the gearbox internals; I use marine wheel bearing grease on my bike bearings, and it contains aluminum and calcium compounds, for example.