I've not took it in years but the coastal route wasn't in a great condition when I took it before. I think they've remove the 10% off road mud bath up Binn hill but even then its not great, iirc there's an awkward crossing of the A92 (you need to push your bike up steps (or tobe precise an upturned gutter along them). I'd reccommend the Cleish Kinross way too, a bit more climbing involve but a better route. I'd reccomend being selective of Sustrans routes they do tend to wander sometimes.
PS I've no idea the quality of it but Dundee City Council do some
maps which may help. Good luck
Edit: its the way the quiet and balance route in
cyclestreets takes you too (Craiglochart to Lochee is 66.75 miles), you can get it dow to 57mile going by Glenrothes after Kinross but that involves the horrible A92 !