I am interested where you do your driven hunting?
I shoot mainly in France, but also have shot in Germany, and O/U shotguns (mainly 12 bore, but also 16 and 20 bore) are very common. (As is availabilty of slugs in Decathlon!).
Where I would personally regard a shotgun as preferable to a rifle would be where the allees (gaps between blocks of forest) are <20 metres, and the average likely shot is under 50m. Which describes 75% of one entire shoot I attend! In effect, you are shooting at similar ranges, swing and target sizes to driven pheasant (just rather lower!)
I agree with you that a rifle is a better all-rounder, but my experience is that, on a driven grand gibier shoot in wooded country, the difference in ballistics between a 12 bore slug and 9.3mm bullet has not been worth thinking about.
To get back to the OP's question, however, simple maths suggests that a .410 slug has about one quarter the kinetic energy of a similarly-sized 9.3 x 74R bullet (.410" vs .366" bores). That, even if legal, would make the .410" slug at best marginal for driven bore, IMHO. But pretty ideal for roe.