Kodak Research in the UK did much more work on Acutance developers and Kodak Ltd release HDD, they also made a Rodinal type developer Kodinol, neither were available in the US.

It's often forgotten that Kodak's Research facilities in Rochester and Harrow were both set up by Mees after Kodak bought Wratten & Wainwright, and many of the senior staff in both the US &UK had worked together at Wratten & Wainwright. (Up until the1950's).

In practice mainy of these older acutance developers work better with modern T-grain & similar films than they did with films from the late 60's and 70's. So Rodinal gives excellent fine grain with films like APX 100 and Tmax 100 which is why it staged a big revival of usage.

Ian