Hi Richard - thanks for the suggestion. This one is actually already on our Feature Requests list (number 59). Anyone interested in this can vote for it to help move it up the list.
Staggered crissroads and roundaouts are not dealt with well with the direction arrow turn warnings.
eg. at a staggered crossing you want to know to go straight ahead, but actually you get a message to turn right. Because the immediate left is too soon, you do not get the message to then turn left of the device. Simpler if instruction was straight across, or arrow created for staggred junction.
eg. at a roundabout, you need a turn prompt so you know where to position yourself on the road. eg. if turnng right, a right arrow warning turn prompt.