1.6.1 b8cd - although not mentioned in the b8cd release notes, severe issues with German Naval AI continue to exist. To see this for yourself, just run '39 scenario and watch GER Hands off, AI vs AI.
a) GER convoys (and I assume all other nations), will have their convoys go through yellow zones, even though there is indeed another viable path through allowed sea zone. If the sea zone is set to red, transports will indeed bypass the red sea zones. GER AI only has Red on the English Channel, Yellow on other sea regions around the UK, and GER transports sail along the northern and western UK coast line getting murdered.
b) % coverage factor on Escort Missions is now missing (this worked in the previous version of 1.6.1, so its a digression)
c) GER Naval AI continues to allocate raiding missions in Red and Yellow Sea Regions, even though there are plenty of allowed sea regions within range
So, GER Convoy Raiding is still poo poo. Maybe in a good month, Convoy to Sub KDR is 3:1, which is a reason to execute Dontiz without hesitation.