Some more regenerative braking questions

[Foss62]

I know there is another thread, but it seems to have died out without answering very much. I now have a brand new Skoda Superb plug-in hybrid and driving it has raised a few questions:

1. Regenerative braking is either on or off (the other thread mentions different selectable levels but I don’t have that). Apart from the driving ‘feel’ are there any negatives to engaging it all the time? I think the brake pedal engages it anyway (whether or not you select it). The handbook is useless on this point by the way…
2. When the gearbox is used in ‘manual’ mode am I right in thinking that the equivalent of holding in a low gear is just a high level of regenerative braking? If so:
3. Is selecting regenerative braking in drive the equivalent to holding in low gear (i.e. would be accepted as such on an advanced test)?