There are two such roundabouts between Bracknell Towers and Falmer (Beddingham and Southerham). I don't think either of them are what would be called "major interchanges". The jet lanes serve single carriageways, not dual carriageways. Neither of them present any difficulties to drivers who...
Modern roundabout design standards incorporate "jet lanes" to segregate traffic on the roundabout and ensure that there is no need to indicate left before leaving the roundabout. Southerham roundabout at Lewes is a good example. The more of these that are built, the more likely it is that...