I have the Blue Motion T6 28 (2016) and the automatic stop and start causes me the secondary issue you are having "whilst half way round a roundabout the engine just cut out, acted like I'd pulled the key from the ignition". If I always disable (switch off) the auto-stop start every time I start the engine, the fault never occurs. When it does occur if I forget to switch off the autostart it is very scary. Nearly always happens when on a roundabout or when changing down whilst slowing in a sharp corner. Still trying to find an answer. A complete lack of Volkswagen Van dealers in my area means I am still researching a solution. I remember once reading on the forum that it was a problem for which there is a solution but I do not know what that solution is. I am beginning to think that the system finds it hard to cope with Double D'Clutch gear changes. I know they are not necessary any more but it is very hard to change a driving style that was the norm for such a large part of my life. I approached three local auto electricians asking if the Auto Stop/Start can be disabled but they are all so backed up with work that they are not interested in looking at the issue.
