Peaty also had DT Swiss wheels with the grease replaced with oil, to really cut down on friction, as if they weren't fast enough any way.
They seem to do this in RC and inline Skating as well. Seems like one of the more marginal of gains. But I guess if you aren't paying for the bearings, go nuts.
Yeah Minaar and Peaty had special V10s made with an extra 20mm length. They were still probably shorter than the current bikes!