I asked the guy in the shop who was doing all the testing about drag when in the no assistance mode and he said not, but admitted he was concentrating more on the pink light issue rather than anything else. I guess it’s something that will have to be tried, but I hope it doesn’t cause drag.
He also said that leaving it switched on all the time would only have a minimal effect on the battery level, which was a concern of mine - running the battery down while not taking advantage of the assistance.
When I asked about it switching itself on when hurtling downhill, I think he’d forgotten about that, so couldn’t answer. To be honest, if everything else works ok now, I can cope with that issue!
As I said, I think it’s as much a learning curve for them as much as us!