The roof plane tool in Version 2018 is so bad (worse even than 2017) that I've had to revert to 2017 to keep working.
E.g. a rooflight appears with a 'column' of roof surface projecting through the rooflight. It's impossible to insert dormers any more, they have to be created with walls and roof planes, etc, etc.
Please can someone take a comprehensive look at the roof plane tool and make sure it's fit for purpose.