Not sure if this affects the grand and grand new, I have no experience in those types.
Same system on the Grand, a retrofit "one engine at idle" audio warning kit is available. Yes, I've also lifted off with one at idle. Having fronted up to my mistake, I got the blame, not the aircraft. I pointed out the warning upgrade kit was available but they've never bothered with it. The thinking seemed to be if it was a known problem, then I should have known about it and taken more care. Thankfully, no harm was done (apart from to my professional pride) but I know that I'd be down the road if it had been.