That is how Ford’s Hybrids (FHEV) and Plug-in Hybrids (PHEV) work today. The PHEV has a larger battery, so that when you charge it externally, it can be driven in full electric mode for as many miles as the charge lasts. Once the charge is depleted, it reverts to operating similarly to the FHEV, except you’re dragging around the extra weight of the larger battery.
Yes, this is exactly what I meant. I really don't have a good feel for the sweet spot between power, battery size/weight, and charging ability (whether braking or plug in). And I imagine a part of that is just driver preference and how/where you're driving. For me, with the Raptor being my daily driver, I have a 45 minute commute to work, so I don't think I would need the bigger battery/plug in for that much. However, I only use t for commute every other week (car pool), using it only for short trips around town, so perhaps the bigger battery/plug in would be useful in that case. Again, I'm not claiming to have a good deal for what's the best situation, just didn't see why plug in wasn't desired.
@FordTechOne, to clarify what you said in the last sentence, are you saying that a PHEV will not charge by braking until the battery is depleted form a plug in charge?