It it possible Apple overprovisions their batteries such that they only ever charge the physical calls up to an ideal level (~80% or whatever, of nominal Wh cap

It it possible Apple overprovisions their batteries such that they only ever charge the physical calls up to an ideal level (~80% or whatever, of nominal Wh capacity), and then they show in software a 100% charge? If the battery is larger than it needs to be, the extra headroom would allow long usage on a "full" charge while preserving cell longevity. In time when capacity does diminish, software could also raise the full-charge point from ~80% of physical capacity closer to the nominal physical cell capacity. This would be similar to what SSD manufacturers do with drive sizes. There are more memory cells on the die than the sticker capacity, and as cells fall out of use (due to failure or maximum number of write cycles) extra cells are rotated into use to maintain speed and capacity.