I’m inclined to agree with the UR here but don’t know if something else has been agreed regarding motorway lane drops. Whilst it’s possible to exit and continue straight from the middle lane it doesn’t match what the painted road markings say.
However if you move up to the actual physical junction, you can see an invitation in the road paint to take the exit from what was the middle lane.
We don’t have a way of communicating the full complexity of the junction, but I think the lane guidance is as good as we can get it with the tool available. Left lane exit only, right lane ahead only, middle lane can go either way.
Now that I’ve replied, and so the summary screen no longer says 0 replies, it’s unlikely that anyone else will look at this. 
If you want a third opinion or a general discussion, you’d better post to the main forum.
Ian
These aerials show the old lane markings, whereas streetview from Jan 2021 shows it’s been changed more recently. You can just about make out the old paint on the carriageway.
I’ve updated the lane guidance.