ROG:
The test is supposed to reflect driving in real life as much as possible so what would an artic driver do in real life if faced with that situation ?
Wait for a nice old lady with a zimmer frame to stand at the corner or if none were available a cyclist would do, and make the turn of course 
I’m joking of course.
In a real live situation where perhaps the police had blocked the right hand turning due to an accident and strait-on is unsuitable for HGV, then there would be no alternative than to carefully mount the kerb