BTW, the passages you quote seems to be advising against using laptops plugged in with the battery attached -- I'm guessing with non-detachable batteries like the ones in recent MacBooks, the best practice is to unplug them when in use? In any case, it didn't strike me as relevant to my usage of iPads, which I almost never use while plugged in to a power source.
Laptops are a relatively extreme example (hot, high drain, relatively low capacity batts) as opposed to the iPad or iPhone (cool, low drain, relatively high capacity batts) as a result they are used differently. Laptops - usually plugged in, iPhone/iPad - usually unplugged. However, the things that wear the battery still apply to both types.... for the purposes of this thread that is 1) charging to a full 100%/4.2V, 2) the amount of time the battery sits at full or near full charge, and 3) the number of charge cycles the device uses.
The a plugged in laptop is primarily worn through 1) and 2) and the iPad/iPhone through 1) and 3). To some extent 2) as well - ie. if you plug in an iPhone before you go to bed at 10pm, it will hit full charge by midnight.... then it just sits at 100%, or a reasonably high state of charge, for a third of day until you start using it.
Unplugging a laptop when not in use will only save the battery if it is not in a high state of charge - the article discusses 3.92V, about 50% capacity as being the level the batt is free from voltage stress. Unplugging the laptop when the batt is fully charged does nothing.... the battery is still in a high state of charge.
For the Apple laptops with immoveable batts, I think the best practice would be to (assuming 9-5 usage) keep it plugged in from 9-2, run it off batt 2-5, then let it sit 5pm-9am at 50-60% charge. Without a specific app or program (as I mentioned at top) It's too difficult to manage less than 100% charges on a laptop.