I consider the inventors of Diafine to be the experts on two bath developers. Baumann was the company that did the research and popularized this development method. They recommend 5s of gentle agitation initially and then 5s every minute. They warn that too vigorous agitation will result in loss of shadow detail. Two bath developers are all variations on a theme and they are more similar than they are different. Development is a diffusion controlled process and too much agitation will only cause problems.