In the airlines I have flown, both with paper airport analisys and laptop computed performance, acceleration altitude is not an precise altitude, but a band between a minimum altitude (do not accelerate before reaching because of obstacles) and a maximum altitude (accelerate before reaching due to engine time limitation at TOGA thrust).
So in the case described, I guess you could just wait till 1,800 ft and turn while acceleratin. So you start the turn earlier and with a shorter radius of turn. If the procedure specifies a unique acceleration altitude, I guess you should follow it, although I can't see why accelerate at 1,300 and then turn at 1,800.
Anyway, it is not good to have a doubt in a sim assessment. Ask the examiner and do it the way he tells you (right or wrong)